Strengthening Japan’s defense in response to Russia’s aggression against Ukraine

Tetsuro FujimotoSTRENGTHENING JAPAN’S

DEFENSE IN RESPONSE TO

RUSSIA’S AGGRESSION

AGAINST UKRAINE

A STUDY FROM THE PERSPECTIVE

OF INTEGRATED AIR AND MISSILE

DEFENSE CAPABILITIES

Photo: Hidenori Nagai/The Yomiuri Shimbun via Reuters Connect

FOREIGN POLICY AT BROOKINGS 1Executive summary

Japan’s 2022 National Security Strategy empha -

sizes the importance of maintaining sovereignty,

ensuring territorial integrity, and securing the

safety of its citizens. To achieve these ends,

Japan aims to strengthen its defense system,

enhance the Japan-U.S. alliance’s deterrence and

response capabilities, and reinforce cooperation

with like-minded countries. Given that Japan

is an island nation, air and maritime transport

capabilities for rapid deployment and supply are

crucial.

However, the Japan Self-Defense Forces (SDF)

faces several challenges in its current state of

readiness. If ground-deployed missile defense

systems or medium-range air defense missiles

are subjected to concentrated enemy attacks,

the destruction of fire control systems could

render them inoperable, even if ammunition

remains. Additionally, the lack of compatibility

between systems makes it difficult to repair

damaged units using parts from other units or

to supplement ammunition supplies from other

sources within the arsenal. Furthermore, chal -

lenges related to rapid production raise concerns

about Japan’s ability to sustain weapon and

ammunition supplies during prolonged conflicts.

This paper proposes three measures to address

these challenges. The first is to develop

combined offensive and defensive systems to

enhance operational flexibility and strengthen

sustained combat capabilities under concen -

trated enemy attacks. The second is to invest in

low-cost, mass-produced interception systems

such as short-range surface-to-air missiles and

man-portable air defense systems to counter

large numbers of low-end aerial threats. The third

is to utilize 3D-printing (also known as “additive

manufacturing,” or AM) technology to ensure a

rapid and stable supply of weapons and ammu -

nition, thereby overcoming the limitations of

traditional supply chains.However, implementing these measures involves

several challenges, including ensuring system

compatibility, developing a strategy for AM

technology, and addressing policy and budgetary

constraints. In order for integration to run

smoothly, any new systems must be compatible

with existing SDF equipment. Additionally, a

comprehensive AM technology strategy must be

in place to address potential disruptions in the

supply chain. Overcoming policy and budgetary

constraints requires obtaining approval and

securing funding for new defense projects not

included in the current Defense Buildup Program.

Though these challenges are significant, they can

be overcome if addressed in the right way.

The recommendations put forth in this paper to

enhance the SDF’s combat sustainment capabili -

ties align with Japan’s national security interests

and are crucial for maintaining regional peace

and stability. Implementing these recommenda -

tions would not only improve Japan’s defense

capabilities but also strengthen the Japan-U.S.

alliance and, potentially, further advance Japan’s

overall industrial and technological progress.

By addressing new threats and preparing for

prolonged conflicts, Japan can ensure its peace

and stability in an increasingly uncertain world.

Introduction

Japan’s security environment has become

increasingly complex and severe due to Russia’s

aggression against Ukraine and the military

advancements of countries neighboring Japan,

such as China and North Korea. This situation

underscores the urgent need to enhance the

combat sustainment capabilities of Japan’s

Self-Defense Forces (SDF), in the interest of

maintaining peace and stability in Japan and the

Indo-Pacific region.

2 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEThis paper argues that strengthening the SDF’s

combat sustainment capability is crucial for

Japan’s national security. Three primary recom -

mendations are made to achieve this end: the

first is to develop combined offensive and defen -

sive ground systems, the second is to enhance

low-end interception measures, and the third

is to establish a rapid and stable supply system

using 3D-printing (also known as “additive manu -

facturing” technology).

The development of combined offensive and

defensive ground systems will result in greater

operational flexibility and will enable the SDF to

sustain combat capabilities even under concen -

trated enemy attacks. Enhancing low-end inter -

ception measures, such as short-range surface-

to-air missiles and man-portable air defense

systems, will allow the SDF to effectively counter

large numbers of low-end aerial threats. Finally,

the use of additive manufacturing (AM) tech -

nology, which is not subject to the limitations of

traditional supply chains, will ensure a rapid and

stable supply of weapons and ammunition.

These recommendations are supported by the

outcomes of recent conflicts in which the effec -

tiveness of integrated air and missile defense

(IAMD) systems, the importance of low-end

interception measures in countering mass aerial

threats, and the advantages of AM technology

in maintaining a resilient supply chain have been

made clear. By addressing these key areas,

Japan can significantly enhance its defense

capabilities and contribute to regional stability.

Japan’s security

environment

MILITARY TRENDS IN NEIGHBORING

COUNTRIES AND REGIONS

As described in Japan’s 2022 National Security

Strategy, China’s external stance, military activi -

ties, and other nonmilitary actions have become a matter of serious concern for Japan and repre -

sent an unprecedented strategic challenge to the

international community.1 Backed by substantial

increases in defense spending, China is rapidly

enhancing its military capabilities across a broad

spectrum, focusing on sea power, air power, and

nuclear and missile capabilities. The Chinese

navy is the world’s largest, comprising over 370

ships and submarines, including more than 140

major surface combatants. The Chinese navy is

rapidly strengthening its power: it is currently

building its fourth amphibious assault ship and

commissioning its third aircraft carrier.2 The

Chinese air force has over 3,150 aircraft, of

which approximately 2,400 are combat aircraft

(including bombers), and is rapidly enhancing

its air power. Recent advancements include the

deployment of the J-20 fifth-generation fighter.3

The U.S. Department of Defense estimates

that the People’s Liberation Army (PLA) already

possesses over 500 operational nuclear weapons

and projects that it will probably have more than

1,000 operational nuclear warheads by 2030.4

The U.S. Department of Defense also estimates

that the PLA has 2,850 ballistic missiles and 300

ground-launched cruise missiles (GLCMs) with

ranges exceeding 1,500 km.5

China has intensified the activities of its naval

and air forces in the seas and airspace around

Japan and the Western Pacific and has used

force to unilaterally change the status quo in

the East and South China Seas. In August 2022,

when U.S. House Speaker Nancy Pelosi visited

Taiwan, China launched a total of nine ballistic

missiles into the waters around Taiwan, five of

which landed in Japan’s exclusive economic

zone (EEZ). Since 2020, the number of Chinese

military aircraft crossing the Taiwan Strait median

line has significantly increased, particularly after

Pelosi’s visit.6 While China maintains a policy of

peaceful unification with Taiwan, it has not ruled

out the possibility of using force. In October

2022, during the 20th National Congress of

the Chinese Communist Party, President Xi

Jinping stated that “we will continue to strive for

peaceful reunification with the greatest sincerity

and utmost effort, but we will never promise to

renounce the use of force.”7 Against this back -

FOREIGN POLICY AT BROOKINGS 3drop, in testimony to Congress on March 20,

2024, Admiral John Aquilino, former commander

of the Indo-Pacific Command, stated, “All indi -

cations point to the PLA meeting President Xi

Jinping’s directive to be ready to invade Taiwan

by 2027.”8 In 2023, the Center for Strategic and

International Studies, a U.S.-based think tank,

released the results of a Taiwan Strait contin -

gency simulation,9 and the Japan Institute of

International Affairs conducted a similar simu -

lation of its own.10 These trends indicate that

China’s external posture and military actions are

heightening tensions around the Taiwan Strait,

causing significant concern for the international

community, including Japan.

North Korea’s military activities pose a graver

and more imminent threat to Japan’s national

security than ever before. Over the past decade,

North Korea has rapidly advanced its nuclear and

missile development. In 2022 alone, North Korea

conducted an unprecedented number of missile

tests, launching at least 59 missiles in total on

31 occasions. The Japan Ministry of Defense

(JMOD) estimates that one of the missiles flew

approximately 4,600 km over Japan.11 The launch

patterns of North Korean ballistic missiles have

become more diverse and complex, indicating a steady improvement in their missile capabilities.

It is anticipated that North Korea will continue

to focus on the research, development, and

operational enhancement of various weapons,

including nuclear weapons and missiles, based

on the “five-year plan for the development of

the defense science and the weapon system”

announced at the 8th Congress of the Korean

Workers Party in January 2021.12

Even amid its aggression against Ukraine, Russia

continues its military activities elsewhere, which

include large-scale exercises in the Far East.

These actions, coupled w

...

Tetsuro FujimotoSTRENGTHENING JAPAN’S

DEFENSE IN RESPONSE TO

RUSSIA’S AGGRESSION

AGAINST UKRAINE

A STUDY FROM THE PERSPECTIVE

OF INTEGRATED AIR AND MISSILE

DEFENSE CAPABILITIES

Photo: Hidenori Nagai/The Yomiuri Shimbun via Reuters Connect

FOREIGN POLICY AT BROOKINGS 1Executive summary

Japan’s 2022 National Security Strategy empha -

sizes the importance of maintaining sovereignty,

ensuring territorial integrity, and securing the

safety of its citizens. To achieve these ends,

Japan aims to strengthen its defense system,

enhance the Japan-U.S. alliance’s deterrence and

response capabilities, and reinforce cooperation

with like-minded countries. Given that Japan

is an island nation, air and maritime transport

capabilities for rapid deployment and supply are

crucial.

However, the Japan Self-Defense Forces (SDF)

faces several challenges in its current state of

readiness. If ground-deployed missile defense

systems or medium-range air defense missiles

are subjected to concentrated enemy attacks,

the destruction of fire control systems could

render them inoperable, even if ammunition

remains. Additionally, the lack of compatibility

between systems makes it difficult to repair

damaged units using parts from other units or

to supplement ammunition supplies from other

sources within the arsenal. Furthermore, chal -

lenges related to rapid production raise concerns

about Japan’s ability to sustain weapon and

ammunition supplies during prolonged conflicts.

This paper proposes three measures to address

these challenges. The first is to develop

combined offensive and defensive systems to

enhance operational flexibility and strengthen

sustained combat capabilities under concen -

trated enemy attacks. The second is to invest in

low-cost, mass-produced interception systems

such as short-range surface-to-air missiles and

man-portable air defense systems to counter

large numbers of low-end aerial threats. The third

is to utilize 3D-printing (also known as “additive

manufacturing,” or AM) technology to ensure a

rapid and stable supply of weapons and ammu -

nition, thereby overcoming the limitations of

traditional supply chains.However, implementing these measures involves

several challenges, including ensuring system

compatibility, developing a strategy for AM

technology, and addressing policy and budgetary

constraints. In order for integration to run

smoothly, any new systems must be compatible

with existing SDF equipment. Additionally, a

comprehensive AM technology strategy must be

in place to address potential disruptions in the

supply chain. Overcoming policy and budgetary

constraints requires obtaining approval and

securing funding for new defense projects not

included in the current Defense Buildup Program.

Though these challenges are significant, they can

be overcome if addressed in the right way.

The recommendations put forth in this paper to

enhance the SDF’s combat sustainment capabili -

ties align with Japan’s national security interests

and are crucial for maintaining regional peace

and stability. Implementing these recommenda -

tions would not only improve Japan’s defense

capabilities but also strengthen the Japan-U.S.

alliance and, potentially, further advance Japan’s

overall industrial and technological progress.

By addressing new threats and preparing for

prolonged conflicts, Japan can ensure its peace

and stability in an increasingly uncertain world.

Introduction

Japan’s security environment has become

increasingly complex and severe due to Russia’s

aggression against Ukraine and the military

advancements of countries neighboring Japan,

such as China and North Korea. This situation

underscores the urgent need to enhance the

combat sustainment capabilities of Japan’s

Self-Defense Forces (SDF), in the interest of

maintaining peace and stability in Japan and the

Indo-Pacific region.

2 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEThis paper argues that strengthening the SDF’s

combat sustainment capability is crucial for

Japan’s national security. Three primary recom -

mendations are made to achieve this end: the

first is to develop combined offensive and defen -

sive ground systems, the second is to enhance

low-end interception measures, and the third

is to establish a rapid and stable supply system

using 3D-printing (also known as “additive manu -

facturing” technology).

The development of combined offensive and

defensive ground systems will result in greater

operational flexibility and will enable the SDF to

sustain combat capabilities even under concen -

trated enemy attacks. Enhancing low-end inter -

ception measures, such as short-range surface-

to-air missiles and man-portable air defense

systems, will allow the SDF to effectively counter

large numbers of low-end aerial threats. Finally,

the use of additive manufacturing (AM) tech -

nology, which is not subject to the limitations of

traditional supply chains, will ensure a rapid and

stable supply of weapons and ammunition.

These recommendations are supported by the

outcomes of recent conflicts in which the effec -

tiveness of integrated air and missile defense

(IAMD) systems, the importance of low-end

interception measures in countering mass aerial

threats, and the advantages of AM technology

in maintaining a resilient supply chain have been

made clear. By addressing these key areas,

Japan can significantly enhance its defense

capabilities and contribute to regional stability.

Japan’s security

environment

MILITARY TRENDS IN NEIGHBORING

COUNTRIES AND REGIONS

As described in Japan’s 2022 National Security

Strategy, China’s external stance, military activi -

ties, and other nonmilitary actions have become a matter of serious concern for Japan and repre -

sent an unprecedented strategic challenge to the

international community.1 Backed by substantial

increases in defense spending, China is rapidly

enhancing its military capabilities across a broad

spectrum, focusing on sea power, air power, and

nuclear and missile capabilities. The Chinese

navy is the world’s largest, comprising over 370

ships and submarines, including more than 140

major surface combatants. The Chinese navy is

rapidly strengthening its power: it is currently

building its fourth amphibious assault ship and

commissioning its third aircraft carrier.2 The

Chinese air force has over 3,150 aircraft, of

which approximately 2,400 are combat aircraft

(including bombers), and is rapidly enhancing

its air power. Recent advancements include the

deployment of the J-20 fifth-generation fighter.3

The U.S. Department of Defense estimates

that the People’s Liberation Army (PLA) already

possesses over 500 operational nuclear weapons

and projects that it will probably have more than

1,000 operational nuclear warheads by 2030.4

The U.S. Department of Defense also estimates

that the PLA has 2,850 ballistic missiles and 300

ground-launched cruise missiles (GLCMs) with

ranges exceeding 1,500 km.5

China has intensified the activities of its naval

and air forces in the seas and airspace around

Japan and the Western Pacific and has used

force to unilaterally change the status quo in

the East and South China Seas. In August 2022,

when U.S. House Speaker Nancy Pelosi visited

Taiwan, China launched a total of nine ballistic

missiles into the waters around Taiwan, five of

which landed in Japan’s exclusive economic

zone (EEZ). Since 2020, the number of Chinese

military aircraft crossing the Taiwan Strait median

line has significantly increased, particularly after

Pelosi’s visit.6 While China maintains a policy of

peaceful unification with Taiwan, it has not ruled

out the possibility of using force. In October

2022, during the 20th National Congress of

the Chinese Communist Party, President Xi

Jinping stated that “we will continue to strive for

peaceful reunification with the greatest sincerity

and utmost effort, but we will never promise to

renounce the use of force.”7 Against this back -

FOREIGN POLICY AT BROOKINGS 3drop, in testimony to Congress on March 20,

2024, Admiral John Aquilino, former commander

of the Indo-Pacific Command, stated, “All indi -

cations point to the PLA meeting President Xi

Jinping’s directive to be ready to invade Taiwan

by 2027.”8 In 2023, the Center for Strategic and

International Studies, a U.S.-based think tank,

released the results of a Taiwan Strait contin -

gency simulation,9 and the Japan Institute of

International Affairs conducted a similar simu -

lation of its own.10 These trends indicate that

China’s external posture and military actions are

heightening tensions around the Taiwan Strait,

causing significant concern for the international

community, including Japan.

North Korea’s military activities pose a graver

and more imminent threat to Japan’s national

security than ever before. Over the past decade,

North Korea has rapidly advanced its nuclear and

missile development. In 2022 alone, North Korea

conducted an unprecedented number of missile

tests, launching at least 59 missiles in total on

31 occasions. The Japan Ministry of Defense

(JMOD) estimates that one of the missiles flew

approximately 4,600 km over Japan.11 The launch

patterns of North Korean ballistic missiles have

become more diverse and complex, indicating a steady improvement in their missile capabilities.

It is anticipated that North Korea will continue

to focus on the research, development, and

operational enhancement of various weapons,

including nuclear weapons and missiles, based

on the “five-year plan for the development of

the defense science and the weapon system”

announced at the 8th Congress of the Korean

Workers Party in January 2021.12

Even amid its aggression against Ukraine, Russia

continues its military activities elsewhere, which

include large-scale exercises in the Far East.

These actions, coupled with strategic coordina -

tion with China, pose strong security concerns

for the Indo-Pacific region, including for Japan.

In fact, Russia has been enhancing its military

presence around Japan. Over the past decade, it

has deployed and modernized various weapons

systems, such as the Bastion and Bal coastal

defense missile systems and Su-35S fighters, in

the Far East, including in the Japanese Northern

Territories. At the same time, joint activities with

China have increased in frequency and scale.

Russia and China have been strengthening

their cooperation through annual joint flights of

bombers and joint naval operations near Japan’s

waters.13 This trend is expected to continue.

4 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEFIGURE

Military trends in Japan’s neighboring countries and regions14

EMERGING WAYS OF WARFARE: NEW

DOMAINS AND TECHNOLOGIES

Russia’s approach to warfare in its aggres -

sion against Ukraine has significantly shifted

from traditional methods. Prior to its aggres -

sion against Ukraine, Russia had relied on a

fairly conventional methodology, focusing on

air, sea, and land invasions. As described in

Japan’s National Defense Strategy, Russia’s new

approach incorporates not only these traditional

modes but also large-scale missile attacks,

using ballistic and cruise missiles with enhanced

precision-strike capabilities; hybrid warfare,

involving information-warfare tactics such as

false flag operations; utilization of the space,

cyber, and electromagnetic domains; and asym -

metric attacks using unmanned assets. This new

approach also incorporates actions and rhetoric

that could be interpreted as threats of nuclear

force.15 In 2015, China established the Strategic Support

Force to enhance its capabilities in the domains

of space, cyber, and electromagnetic warfare.

In April 2024, this force was disbanded, and a

new Information Support Force was created.

The space and cyber divisions previously under

the Strategic Support Force were reorganized

into the Aerospace Force and Cyberspace

Force, respectively.16 This move appears to be

an attempt to further strengthen capabilities

in space, cyber, and electromagnetic domains.

Additionally, China has proposed the concept

of “intelligentized warfare.”17 This involves

conducting an integrated war not only across

land, sea, air, and space but in the electromag -

netic, cyber, and cognitive domains as well,

using intelligentized weapons and equipment and

operational methods based on IoT information

systems. The aim of this approach is to enhance

integrated operational capabilities by combining

traditional and new methods of warfare.18

FOREIGN POLICY AT BROOKINGS 5Acquiring the capability to respond to these new

warfare methods is a major challenge in building

future defense capabilities.

RUSSIA’S INVASION OF UKRAINE

Prior to its full-scale invasion of Ukraine in

February 2022, Russia conducted cyberattacks

and waged information warfare, while also

threatening the use of nuclear weapons.19 Shortly

after the invasion began, Russia executed a

concentrated offensive involving space, cyber,

and electromagnetic attacks, alongside infor -

mation warfare, massive missile barrages with

ballistic and cruise missiles, aerial assaults, and

rapid ground incursions.20 This intense blitzkrieg

aimed to defeat Ukraine without leaving time

for other countries to intervene, thereby forcing

Ukraine into early submission. Drawing on the

success of the 2014 Crimea annexation, Russia

likely estimated that pairing hybrid warfare with

a blitzkrieg-style offensive could quickly subdue

the Zelenskyy administration.

Russia’s new method of warfare, characterized

by concentrated attacks, inflicted significant

damage on Ukraine’s operational bases and air

defense systems immediately after the invasion

began. Consequently, Russian aircraft were

able to operate freely in Ukrainian airspace and

conduct attacks.21 However, Ukrainian surface-

to-air missiles that survived the initial onslaught

posed a substantial threat to Russian air power,

significantly reducing the frequency of medium-

and high-altitude incursions by Russian aircraft

into Ukrainian airspace.22 Russian ground forces

advanced to within 30 kilometers north of Kyiv23

but faced fierce resistance from Ukrainian forces.

Their difficulties were compounded by logistical

issues such as fuel shortages, which ultimately

led to the failure of Russia’s ground assault on

Kyiv.24

Russia’s aggression against Ukraine continues

and has become prolonged. One reason for the

prolonged invasion is that Western countries,

in response to repeated nuclear threats from

Russian President Vladimir Putin, have provided restrained support to Ukraine to avoid nuclear

escalation, and the Ukrainian military has also

had to conduct restrained operations.25 In this

prolonged invasion, both Ukraine and Russia are

compensating for conventional manpower short -

ages by employing an unprecedented number of

unmanned aerial vehicles (UAVs). For both sides,

the effective deployment of large numbers of

UAVs and the ability to counter the opponent’s

UAVs are increasingly critical.26 Additionally, in

a prolonged military confrontation, the ability

to mass-produce and procure weapons and

ammunition, including UAVs, plays a critical

role in determining the outcome. The Ukrainian

military, while receiving Western support, is

also mass-producing its own FPV (first-person

view) drones. Meanwhile, Russia continues to

receive substantial weapons and ammunition

support from Iran and North Korea,27 in addi -

tion to producing missiles and UAVs at its own

facilities.28 Ultimately, the side with the supe -

rior weapons and ammunition supply holds the

advantage.

Considerations for

Japan’s defense

Since Japan is an island nation, access to

Japanese territory must be by air or sea. If an

adversary were to invade Japan, it would have

difficulty conducting a ground invasion using

land-based forces. The enemy would first need

to degrade the SDF’s operational bases and

capabilities, then gain temporary regional air and

sea superiority, and then launch invasion forces

by air or sea.

Japan’s territory consists of approximately

14,000 islands and stretches about 3,000 km in

all directions.29 Therefore, when Japan recog -

nizes an armed attack or existential crisis and

responds, the SDF will deploy units and accu -

mulate supplies as necessary. Particularly when

conducting maneuver deployments to islands or

transporting supplies, air or water transport is

required. Additionally, islands generally have a

6 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINElimited number of airports and harbors, and those

that do exist are often small, making it difficult for

large aircraft to land or for naval vessels to dock.

As for transport between islands, the SDF is

unable to provide land transportation except

when bridges are built between islands.

Otherwise, Japan relies heavily on air and water

transport for importing goods. In the event of an

armed attack against Japan, the SDF may have

to supply weapons and ammunition by air and

sea while under missile attack.

As described above, while threats from the

outside need to cross the ocean, by air or

by water, to invade Japan, Japan itself faces

constraints in supplying arms and ammunition

due to the high possibility of being forced to rely

on air and water transport under enemy attack.

Given these circumstances, the SDF needs to

build the capacity and readiness to continue

fighting tenaciously in an island region to achieve

a desirable end state for Japan.

Enhancing SDF

combat sustainment

capabilities: IAMD

systems

In light of Russia’s aggression against Ukraine,

it is crucial for the SDF to be able to continue

fighting tenaciously even when subjected to

concentrated attacks employing new combat

styles and to avoid running out of weapons and

ammunition in the event of a prolonged conflict.

In other words, enhancing the SDF’s combat

sustainment capability is key.

Based on the current status of the SDF’s IAMD

systems, three specific measures can be taken to

strengthen the SDF’s combat sustainment capa -

bility. The first is to increase operational flexibility

by developing combined offensive and defensive

ground systems. The second is to address quan -titative threats by enhancing low-end intercep -

tion methods. The third is to ensure a rapid and

stable supply of materials through 3D-printing

technology. The first two are short-to-medium-

term measures, while the third is a medium-to-

long-term measure.

THE CURRENT STATUS OF THE SDF’S

IAMD SYSTEMS

The High-End Air Defense System

The SDF’s current ballistic missile defense (BMD)

protocol utilizes a multilayered defense system

that integrates upper-tier interceptions by

Aegis ships (SM-3) and lower-tier interceptions

by Patriot systems (PAC-3 and PAC-3 Missile

Segment Enhancement, or MSE) through the

Japan Aerospace Defense Ground Environment

(JADGE) automated warning and control system.

This system includes eight Aegis ships operated

by the Maritime Self-Defense Force (MSDF)

and Patriot units under the purview of the Air

Self-Defense Force (ASDF)—specifically, four

air defense missile groups and 24 air defense

missile fire units. The ASDF’s air defense units

are widely distributed across Japan, from

Hokkaido to Okinawa, and all units can launch

PAC-3 MSE missiles. This deployment allows for

rapid maneuvering and interception readiness

as the situation demands. Additionally, the ASDF

operates 28 fixed warning and control radar sites

across Japan, 17 of which can detect and track

ballistic missiles.30

In terms of air defense systems beyond BMD, the

ASDF’s Patriot systems can also intercept aircraft

and cruise missiles using Guidance Enhanced

Missiles and PAC-3 MSEs.31 The Ground Self-

Defense Force (GSDF) has a similar capability

with its Type 03 medium-range surface-to-air

missile (SAM). The GSDF will operate a total of

14 Type 03 medium-range SAM units (improved

version) by the end of FY 2032.32 Furthermore,

the ASDF and GSDF jointly possess the Type

11 short-range SAM as a successor to the older

Type 81 system, with recent upgrades including

the ability to intercept cruise missiles. The ASDF

FOREIGN POLICY AT BROOKINGS 7and GSDF are currently replacing Type 81 short-

range SAMs with Type 11 short-range SAMs,33

and several units have already commenced

operations with these new systems.34

Regarding sensors, the ASDF possesses 11 radar

units from the aforementioned 28 fixed warning

and control radar sites that are not designated

for ballistic missile defense,35 as well as J/

TPS-102A mobile warning and control radar units

as backups for the fixed warning and control

radar.36 Additionally, the ASDF operates E-767

airborne warning and control system aircraft,

both E-2C and E-2D, ensuring a robust surveil -

lance posture.37

The low-end air defense system

The SDF has been in possession of the so-called

legacy SAM for decades. Particularly, the GSDF

has long been in possession of the modified

Hawk and the Type 93 short-range SAMs, and

they are currently in operation, but the decision

was made to suspend their use in the FY 2024

budget.38 The successor to the improved Hawk

is the Type 03 medium-range SAM, while the

successor to the Type 93 short-range SAM is

the new short-range SAM.39 The new short-

range SAM will undergo further development,

with the aim of improving its ability to counter

cruise missiles while also reducing costs. The

Acquisition, Technology & Logistics Agency

(ATLA) plans to conduct practical tests of the

new short-range SAM until FY 2026.40 In addition,

the GSDF possesses the Type 91 mobile surface-

to-air guided missile (MANPAD).41

The following section outlines, based on the

above information, three specific means for

strengthening the SDF’s joint warfighting capa -

bility from an IAMD perspective.THREE SPECIFIC MEASURES FOR

STRENGTHENING THE SDF’S JOINT

WARFIGHTING CAPABILITY

#1: Developing combined offensive and defen -

sive ground systems for operational flexibility

Possible combat scenarios

At the onset of Russia’s invasion of Ukraine,

Russia aimed to capture Kyiv early by launching

attacks in the space, cyber, and electromag -

netic domains; conducting saturation attacks

with ballistic and cruise missiles; and executing

cross-domain, concentrated airstrikes. These

efforts were intended to destroy the Ukrainian

military’s operational bases, forces, and commu -

nication networks. One hour before the aggres -

sion against Ukraine began, Russia initiated

cyberattacks on the KA-SAT satellite and other

communication networks to disrupt Ukraine’s

information systems.42 In the electromagnetic

domain, Russia used aircraft-mounted electronic

jamming devices and E-96M aerial decoys to

disrupt Ukraine’s air defense capabilities.43

Russia’s saturation attacks with ballistic and

cruise missiles primarily targeted Ukraine’s long-

range early warning radars, SAM sites, command

centers, airfields, and ammunition depots. The

resulting damage rendered the Ukrainian Air

Force unable to detect Russian aircraft and

launch missiles from the SAM sites in the coun -

try’s southern regions that are relatively close to

Russian territory.44 In total, Russia launched 2,154

missiles at Ukrainian cities and regions within the

first two months of the invasion.45

The Russian Air Force deployed Su-34 fighter

jets approximately 140 times per day immediately

after the invasion began, conducting over 100

attacks in the first three days alone. These strikes

targeted Ukraine’s long-range early warning

radars, bases, ammunition depots, and mobile

SAM units.46 Concentrating its forces across all

domains at the outset, Russia aimed to destroy

the operational bases, forces, and communication

networks of the Ukrainian military.

8 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEChina has adopted a similar approach to warfare:

its concept of intelligentized warfare centers

on the integration of traditional and new warf -

ighting methods with the goal of heightening the

country’s capability to conduct concentrated,

effective attacks. In light of China’s develop -

ments in this area, the Center for Strategic and

International Studies has anticipated in its afore -

mentioned Taiwan simulation that the operational

bases and forces of Japan, the United States,

and Taiwan would suffer significant damage from

large-scale attacks by Chinese ballistic missiles,

cruise missiles, and aerial assaults.47

Current challenges facing the SDF

One issue facing the SDF is the lack of redun -

dancy in ground-based the systems such as

SAMs and SSMs. In the event of cross-domain

concentrated attacks by the enemy, it would be

extremely difficult to keep all the SDF’s assets

intact. The SDF’s Patriot systems and medi -

um-range SAM systems are particularly vulner -

able in this regard. As seen in the example of

Russia’s aggression against Ukraine, the enemy

tends to conduct large-scale attacks on opera -

tional bases, air defense systems, and airpower

to gain air superiority.

Ground-based assets such as SAMs and Type 12

SSMs are expected to be deployed to operational

fronts, including island areas, due to Japan’s

defense requirements. If the Patriot missile

fire control system deployed on an island were

destroyed by concentrated enemy attacks, even

if there were plenty of PAC-3 MSE ammunition

remaining, that fire unit would be unable to

operate. The same applies to the Type 03 medi -

um-range SAM and Type 12 SSM.

If units with the same systems are deployed in

contiguous areas, damaged units can be repaired

using components, missiles, and personnel from

other units, thus enabling them to remain in

operation. If this is not the case, damaged units

cannot continue combat until air- or sea-based

support arrives from outside the island. In such

a challenging environment, with the enemy continuing missile and air attacks and naval

invasions, personnel on the ground would have

no choice but to request support from higher

command and wait for air or sea transport while

conserving remaining components and ammuni -

tion.

Another issue is the lack of compatibility

between systems. The Patriot systems, Type 03

medium-range SAMs, and Type 12 SSMs are not

compatible with each other and have different

operational procedures. Thus, if components of

one system are damaged, units cannot recon -

figure components, ammunition, or personnel

with other systems to continue operations. Even

if the components themselves are not damaged,

any unit that runs out of missiles must wait for

ammunition supplies from outside the island to

arrive before resuming operation. In sum, the lack

of compatibility among these systems makes

them insufficient for sustained operations.

Necessary SDF capabilities

Given the above, it is imperative that the SDF

is able to flexibly reorganize and persistently

continue combat operations even if damage

is sustained from the enemy’s cross-domain

concentrated attacks. To achieve this end, the

SDF should strive for operational flexibility and

sustained combat capability that go beyond the

framework of IAMD, including standoff defense

capabilities.

In particular, as long as SAM systems remain

operational, it is possible to restrict enemy

aircraft operations and protect operational

bases and units. In March of 2022, about a

week into Russia’s invasion of Ukraine, Ukrainian

SAMs, which had survived the initial attacks,

became a significant threat, heavily reducing

the Russian Air Force’s incursions into Ukrainian

airspace at medium and high altitudes.48 As a

result, the Russian military found it difficult to

gain air superiority, which is one of the reasons

why its blitzkrieg-style advance on Kyiv was

unsuccessful. Furthermore, SAMs can protect

operational bases and units from enemy air and

FOREIGN POLICY AT BROOKINGS 9missile attacks. This capability contributes to the

success of Japan-U.S. agile combat operations,

temporarily dispersing and withdrawing fighter

jets, and supporting counterattacks through

standoff defense capabilities. Improving the

sustained combat capabilities of SAM units can

thus heighten the effectiveness of SDF inte -

grated operations and Japan-U.S. joint opera -

tions.

SSM units can prevent the approach of enemy

forces from the sea by destroying vessels before

they land. As long as the SDF prevents enemy

forces from landing, Japan’s territory will not be

captured, and the enemy’s war objectives can

be thwarted. It is therefore highly desirable to

enable SSM units to persistently continue combat

operations.

Strengthening the sustained combat capabili -

ties of SAM and SSM units will allow the SDF to

repeatedly intercept enemy attacks, regardless

of how many are launched; this, in turn, will

lower the odds of success for a blitzkrieg-style

landing invasion. Repelling enemy attacks in

this manner would allow SDF ground forces

to reorganize according to the situation and

to continue fighting persistently, breaking the

enemy’s will and securing the time and founda -

tion needed for counterattacks by Japan-U.S. air

forces. Ultimately, the SDF will be able to prevent

enemies from achieving their war objectives and

enhance deterrence against invasion.

Recommendations

This paper proposes the development of

combined offensive and defensive ground

systems, with both offensive and defensive capa -

bilities, is proposed. This would enhance the effec -

tiveness of the SDF’s standoff defense and IAMD

capabilities. This is not about developing some -

thing entirely new but, rather, about developing a

platform that utilizes a multi-mission fire control

system and launchers capable of firing Patriot

missiles, Type 03 medium-range SAMs, and Type

12 SSMs. In other words, the goal is to operate

three types of missiles within a single system.Achieving this goal would significantly change

the way in which the SDF conducts combat oper -

ations. If, for example, the SDF were to deploy

three of the multi-mission ground units described

above on one of the southwestern islands, it

would be able to continue combat even if the

fire control system for one unit were destroyed

because parts and ammunition from the other

two units would be compatible. Furthermore,

because all personnel would have been trained

to operate the same system, personnel rotation

between units could be carried out flexibly.

Another advantage of the multi-mission ground

system is that ground forces would be able to

flexibly switch between offense and defense in

response to the enemy’s invasion posture. For

example, if a heavy enemy air offensive were

expected, the SDF could use all three units to fire

SAMs. If the aim were to destroy enemy vessels,

all three units could fire SSMs.

Additional standoff defense technologies, such

as the HVGP, for the defense of remote islands,

and hypersonic missiles, are currently under

development.49 If these can be integrated into

the aforementioned ground system, it is believed

that operational flexibility and sustained combat

capability could be further enhanced, making this

a matter worth considering.

#2: Addressing quantitative threats by

enhancing low-end interception measures

Possible combat scenarios

Throughout Russia’s aggression against Ukraine,

both sides are operating drones and unmanned

aerial vehicles on an unprecedented scale. These

UAVs, which are cheap and able to be mass-pro -

duced, can be used for tracking, targeting, and

bombing enemy forces.50

At the beginning of the invasion, Ukraine

successfully operated Turkish-made Bayraktar

UAVs with a range of about 300 km to destroy

Russian armored vehicles and air defense

systems.51 In the summer of 2022, as Russia

10 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEbegan to experience a shortage of ballistic and

cruise missiles and faced a Ukrainian counterof -

fensive, Moscow purchased a large number of

Shahed UAVs from Iran.52 Russia has extensively

used the Shahed, a long-range autonomous UAV

with a range of approximately 1,000 to 1,500

km, to exhaust Ukraine’s air defense missiles.

By December 2023, Russia had launched 3,700

Shahed attacks on Ukraine,53 and even now,

Ukraine continues to face hundreds of Shahed

attacks each month.54

To counter this large-scale offensive, Ukraine has

used FrankenSAMs as well as Western-supplied

anti-aircraft guns and MANPADS to shoot down

Russia’s Shahed UAVs.55 Additionally, Ukraine

has independently developed and deployed long-

range UAVs, such as the UJ-26, with a reported

maximum range of 800 km, to strike infrastruc -

ture within Russia.56

Both Ukraine and Russia are also deploying large

numbers of inexpensive first-person view (FPV)

drones. In January 2024, Ukraine launched the

so-called People’s Drones Project, which mobi -

lized the public to begin manufacturing FPV

drones.57 Although it is unclear whether the goal

was achieved, this initiative aimed to produce

one million FPV drones by the end of 2024 to

compensate for the country’s severe ammunition

shortage. Ukraine is currently using many FPV

drones, each costing around $500, in combi -

nation with reconnaissance drones equipped

with high-performance cameras, which cost

between $1,500 and $3,000, to destroy high-

value Russian equipment such as tanks—these

tactics have allowed the Ukrainian military to

hold its ground in the battle. While the range of

FPV drones is only about 5 to 20 km and their

destructive power is less than that of artillery

shells, their precise guidance makes them

highly effective. Russia is also using FPV drones

to attack Ukraine. These drones are a threat

to front-line soldiers on both sides and have

become a factor in the current stalemate.58Thus, in the prolonged Russia’s aggression

against Ukraine, it has become clear that UAVs

can be effective in compensating for shortages

and inferiority of conventional weapons. It is

expected that in future wars, invading countries

will use not only high-end conventional weapons

but also many UAVs.

China, a neighboring country of Japan,

possesses a wide variety of UAVs for both mili -

tary and civilian use, and their long-range UAVs

are already conducting air activities in the vicinity

of Japan.59 A situation similar to the one in Russia

and Ukraine is by no means out of the question

for Japan.

Current challenges facing the SDF

The SDF has a world-class capability to counter

ballistic missiles, second only to that of the

United States. In particular, the SDF’s theater-

level BMD capability in the vicinity of Japan

is highly developed in terms of C2 systems,

sensors, and shooters. Furthermore, plans are

in place to steadily enhance capabilities against

emerging threats such as hypersonic glide vehi -

cles.

It is crucial to equip the SDF with high-end air

defense systems to counter high-end threats

from the enemy because the SDF would be

powerless against enemy attacks without such

systems. However, high-end equipment generally

comes with high costs and long production and

procurement times, making it difficult to maintain

in large quantities. For example, as of July 2023,

the annual production of PAC-3 MSE missiles in

the United States was 550 units, with Lockheed

Martin aiming for 650 units by 2027.60 These

numbers fall far short of the number of Shahed

UAVs launched by Russia. If the SDF were to use

high-end air defense missiles to counter a large

number of low-end threats from the enemy, the

stockpile of air defense missiles would quickly be

depleted. This would leave the SDF unequipped

to deal with further low-end, as well as any

high-end, threats from the enemy.

FOREIGN POLICY AT BROOKINGS 11Currently, most of the SDF’s low-end air defense

systems are being replaced, under development,

or slated for decommissioning. It is unlikely that

Japan, surrounded by the sea, will suffer signif -

icant damage from FPV drones so long as the

enemy cannot land because these drones have

very short ranges. However, long-range UAVs

would be problematic because they could reach

Japanese territory from a number of different

launch points. Therefore, a shortage of low-end

countermeasures could put Japan in a difficult

situation were it to face a large-scale attack

utilizing long-range UAVs.

Necessary SDF capabilities

In addition to having the capability to intercept

high-end threats from the enemy, the SDF must

be able to counter quantitative low-end threats.

Given that the Ukrainian forces are successfully

and reliably intercepting Shahed UAVs using

FrankenSAMs, anti-aircraft guns, and MANPADS,

intercepting long-range UAVs is not likely to pose

a technical challenge. The key factor is ensuring

a sufficient quantity of low-end interception

measures to address quantitative threats.

Recommendations

The paper proposes the establishment of a

defense posture that combines high-end and

low-end interception means by increasing invest -

ment in interception measures against low-end

threats. This is intended to strengthen IAMD

capabilities.

The requisite supply of low-end interception

missiles could be secured using several means.

The first is to accelerate the replacement of

the Type 81 short-range SAM with the Type 11

short-range SAM. This would not only enhance

the SDF’s ability to counter UAVs but would also

improve response against saturation attacks by

cruise missiles. Although mass production of the

Type 11 short-range SAM began about 14 years

ago,61 the process has been slowed by strict

budget constraints; there is a need to accelerate

the pace at which these missiles are replaced.The second means is to promote the acquisition of

Type 11 short-range SAMs. It goes without saying

that the first step must be to enhance the existing

equipment. The SDF has allocated approximately

10.8 billion JPY (approximately $700 million) for

the acquisition of Type 11 short-range SAMs in the

2024 budget.62 As with the first strategy, the pace

of missile acquisition must be further accelerated.

The third means is to make steady investments

in the development of new short-range SAMs.

The new short-range SAM, which will succeed

the Type 93 short-range SAM, is an improved

version of the Type 11 and is expected to

present fewer technical hurdles than developing

interception capabilities through non-kinetic

means. Additionally, the new short-range SAM is

expected to be more effective in responding to

saturation attacks by cruise missiles compared to

the Type 11 short-range SAM and aims to reduce

cost burdens by reducing the unit production

cost per missile. It is therefore in the SDF’s best

interest to make steady investments in the

development of the new short-range SAM and to

ensure its deployment to units.

The fourth means is to make steady investments

in the development of non-kinetic intercep -

tion means, despite technical and operational

hurdles. Establishing non-kinetic interception

means, such as laser weapons, can significantly

reduce supply concerns, as long as resources

such as electricity remain available. While laser

weapons have not yet been fully operationalized,

the U.S. military has begun limited operations in

the Middle East,63 and the U.K. plans to provide

Ukraine with laser weapons, whose development

is scheduled for completion by 2027, ahead of

schedule.64 Although it takes time to establish

the technology, it is making steady progress,

and its practical application is in sight, which is

important.

The fifth means is investment in MANPADS and

anti-aircraft guns. Their effectiveness in inter -

cepting Shahed UAVs has already been demon -

strated in Russia’s aggression against Ukraine, but

they are similarly effective against large numbers

12 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEof low-end UAVs. Furthermore, these weapons

consume less electricity and fuel, making them

potentially extremely effective for low-end

countermeasures in island defense. Regarding

MANPADS, the SDF has long possessed the Type

91 mobile SAM. It is necessary to thoroughly

consider whether to increase the number of

Type 91s or to develop new MANPADS. Outdated

anti-aircraft guns were scrapped in FY 2021, but

successor equipment has not been introduced.65

Considering Russia’s aggression against Ukraine,

the introduction of new anti-aircraft guns is

certainly worth considering.

In conclusion, it is important to strengthen

the SDF’s combat sustainment capabilities by

combining high-end and low-end interception

means and enhancing readiness to respond to a

large number of low-end threats.

#3: Establishing a quick and stable supply chain

with 3D-printing technology

Possible combat scenarios

One of the most influential factors in Russia’s

invasion of Ukraine has been the supply of

weapons and ammunition. As previously

mentioned, after Russia failed to capture Kyiv

early on, Ukraine counterattacked with weapons

and ammunition support it received from the

United States and other Western countries.

Within the first two months of the invasion,

Russia launched 2,154 ballistic and cruise

missiles against Ukraine.66 Having to fend off

Ukraine’s counterattack while dealing with a

depleted missile supply pushed Russia to the

verge of a disadvantage. However, around

September 2022, Russia began purchasing

and deploying large numbers of Iranian Shahed

UAVs,67 which it used in saturation attacks

to deplete Ukraine’s air defense missiles.

Additionally, around the summer of 2023, Russia

began receiving large quantities of weapons and

ammunition from North Korea and established a

system to produce missiles and other munitions

using its own production base.68Due to a temporary stagnation of U.S. support

and restrained support from other Western

countries, Ukraine’s supply of weapons and

ammunition was depleted during this time.69

This created a significant disparity in munitions

stockpiles between Russia and Ukraine and

allowed Russia to regain momentum, not only

thwarting Ukraine’s counteroffensive attempts

but also beginning to expand the front lines

within Ukrainian territory again.70 The domestic

production of Shahed UAVs further strengthened

Russia’s supply system. Ukraine managed to hold

out during this period by mass-producing FPV

drones. In April 2024, the U.S. Congress passed

a bill that included support for Ukraine,71 causing

the supply of U.S. military weapons and ammu -

nition to Ukraine to resume. This will potentially

improve Ukraine’s situation.

The takeaway from Russia’s invasion of Ukraine

is that in a prolonged military confrontation,

differences in the supply of weapons and ammu -

nition can have a great effect. What is more, it is

highly likely that Russia’s strategy of launching

large quantities of missiles and ammunition

immediately after the start of hostilities will be

emulated at some point. The SDF must therefore

be prepared to intercept such attacks and to

similarly counterattack with large numbers of

missiles and ammunition. It must also prepare for

warfighting scenarios in which both sides’ stock -

piles are significantly depleted.

Japan needs to be prepared for a long-term

war. Conflicts with outside actors attempting

to change the status quo by force are often

drawn out in order to deter nuclear escalation.

Much as Russia and Ukraine have done, the SDF

may need to engage in long-term warfare with

depleted missile and ammunition stockpiles, and

under such circumstances, it is conceivable that

the SDF would need to continue fighting while

producing and procuring weapons and ammuni -

tion.

FOREIGN POLICY AT BROOKINGS 13Current challenges facing the SDF

There are two primary methods for supplying

weapons and ammunition. One is to produce

them domestically, and the other is to purchase

or receive them from other countries. This

discussion will focus on the former, given the

latter’s dependence on international circum -

stances, which can be unpredictable.

The challenges of domestic production lie in the

supply system’s limited ability to respond to long-

term demand—specifically, the difficulty of rapid

production and supply and the lack of resilience

in the supply chain for unexpected situations.

Concerning rapid production and supply, both

the SDF and the supply industry face challenges.

The Japanese Ministry of Defense determines

the quantity of weapons and ammunition to be

procured based on the annual defense budget.

Generally, defense companies adjust the scale

of production lines, technicians, and facilities

according to the fluctuations in procurement

quantity, but maintaining these production

bases involves costs. During peacetime, they

do not establish production lines with long-

term warfare in mind. Moreover, it takes time to

train technicians and invest in facilities, which

means it is difficult to achieve rapid production

increases when situations necessitating them

arise. Furthermore, in an emergency, the SDF

must carry out air and sea transport of weapons

and ammunition to areas under enemy attack;

this takes time and carries the risk of transport

assets being shot down and supply becoming

impossible.

The main difficulties in maintaining supply-chain

resilience during unexpected situations lie on

the industry side. In Japan, as in other coun -

tries, many vendor companies are involved in

production under prime contractors. The cessa -

tion of production by key parts manufacturers

can lead to a halt in the supply of weapons and

ammunition. Some companies are withdrawing

from the defense business due to a decrease in

procurement volume.72 If this trend continues, the SDF may face difficulties in procuring weapons,

ammunition, and parts in the future, poten -

tially leading to reduced equipment operational

rates and delays in ammunition production.

Additionally, there have been many instances in

which production had to be halted due to large-

scale natural disasters in Japan.73

Necessary SDF capabilities

The SDF must establish a system that enables

the rapid and stable supply of weapons and

ammunition in emergencies. Achieving this goal

requires enhancing the supply capabilities of

the defense industry. While some progress can

be made on the industry side—technological

development and increased production volume,

for example—the JMOD and the SDF must take

the lead in driving policy. Sole dependence on

industry efforts will not produce the desired

result.

Recommendations

Although additive manufacturing technology is

still developing, it is steadily expanding its range

of applications, and military forces around the

world have begun investing in it. In recent years,

AM technology has even shown promise in more

complex projects, such as producing high-perfor -

mance components in the space sector.74

In the United States, former President Joe Biden

had been promoting an initiative known as AM

Forward, which encourages large corporations

to place AM-related orders with small and

medium-sized enterprises.75 In January 2021,

the U.S. Department of Defense formulated an

AM strategy and has been promoting the use of

AM technology in each branch of the military.76

Notably, the U.S. Air Force has been using AM

technology to produce parts for fighter jets and

transport aircraft.77 In 2024, the U.S. Air Force

Academy’s Blue Horizon Rocketry Club success -

fully used 3D printers to manufacture and fly a

small UAV within 24 hours.78

14 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEIn September 2023, Japan’s GSDF signed a

contract with an Australian company that manu -

factures 3D printers. The contract includes two

types of printers: one is a large metal 3D printer

capable of quickly producing large metal parts in

minutes to hours, and the other is a rugged and

deployable unit that has been integrated into a

transport container and includes all necessary

auxiliary equipment. These systems provide

groundbreaking opportunities to produce metal

parts on-site and on demand. Additionally,

the contract includes comprehensive training,

support, maintenance, and in-the-field exercise

programs using the printers, ensuring that the

GSDF can fully utilize the potential of this tech -

nology in combat and on base.79 This partnership

will enhance the sustained combat capabilities

of units deployed in island areas and further

strengthen the existing supply chain. The advan -

tages of AM technology can be summarized as

follows:

■3D printing offers a dramatic reduction in

production time.

■With design data available, production

capacity can be significantly increased simply

by adding more 3D printers.

■Since 3D printing can be carried out inside

containers such as vehicle shelters, it can

be used on the front lines in island areas

and can significantly contribute to the

sustained combat capabilities of frontline

units. (However, parts manufactured on-site may have inferior functionality, precision,

and quality compared to those manufac -

tured off-site due to material and equipment

limitations.)

■Since it is possible to produce parts on

demand and on a smaller scale, the risk

of vendor companies withdrawing due to

insufficient demand is reduced. Small-scale

production also reduces storage costs

incurred by the SDF.

■Because the same 3D printers can be utilized

in multiple locations, damage to one produc -

tion site will not cause production to be

halted.

■The ability to share production data digitally

will enhance joint production capabilities with

allies and strengthen joint operational capa -

bilities.

Given these advantages, it is clear that AM tech -

nology contributes to the supply chain’s rapidity

and resilience, and there is no doubt that it will

benefit the SDF’s sustained combat capabilities.

FOREIGN POLICY AT BROOKINGS 15TABLE

Effects and limitations of SDF capability-enhancement measures

MEASURE EFFECTS CONSTRAINTS

Development of combined

offensive and defensive ground

Systems ■Builds an integrated plat -

form for both offensive

and defensive operations,

enabling flexible operational

deployment

■Allows rapid reconstitution by

sharing parts and ammuni -

tion, even when damaged

■Enhances sustained combat

capabilities under concen -

trated enemy attacks ■Creates potential for disputes

over system management

responsibilities between the

(GSDF) and ASDF

■Allows only limited cooper -

ation from the U.S. Army,

especially regarding modifi -

cations to the Patriot system

■Is subject to budgetary

constraints under the current

Defense Buildup Program

Enhancement of low-end inter -

ception measures ■Effectively counters small

UAVs and low-cost aerial

threats

■Reduces consumption of

high-cost interceptors by

utilizing short-range SAMs

and MANPADS

■Establishes a sustainable air

defense system against mass

attacks ■Could cause delays related

to the development and

deployment of non-kinetic

interception means (e.g.,

laser weapons)

■Incurs costs associated with

upgrading existing systems

and developing new ones

■Could lead to temporary

vulnerability due to shortages

of low-cost interceptors

Establishment of a quick and

stable supply system with

3D-printing technology ■Significantly reduces produc -

tion time for parts

■Enables rapid production

sharing with allies via digital

data

■Enhances resilience against

attacks by dispersing

production sites ■Brings challenges related to

manufacturing quality and

consistency (machine differ -

ence)

■Requires additional facilities

for manufacturing equipment

with electronic components

■Is vulnerable to cyberattacks,

including data tampering and

theft

■Has limited applicability to

U.S.-made equipment due to

the lack of domestic design

modification authority

16 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINELimitations and

responses to

implementing

specific measures

There are, of course, several limitations to the

strategies proposed thus far. The following

provides an analysis of them.

LIMITATIONS TO DEVELOPING

A COMBINED OFFENSIVE AND

DEFENSIVE GROUND SYSTEM

Because the combined offensive and defensive

ground system can be operated cross-section -

ally between the Ground and Air Self-Defense

Forces, there is a risk that debates may arise

over which service it should belong to, potentially

hindering the system’s development. If these

debates do not reach a resolution, there is a

risk that development plans will never come to

fruition.

However, the SDF has dealt with such issues

before. In the 1960s, following years of debate,

the Nike SAM held by the GSDF was transferred

to the ASDF,80 proving that mature and thorough

discussions can yield positive results.

Additionally, since the Patriot system, which

constitutes part of the combined offensive

and defensive ground system, is domestically

produced under license,81 its modification

requires cooperation from the U.S. Army, the

original licensor. Because the United States may

not see a clear incentive to support the devel -

opment of a combined offensive and defensive

ground system, which is a technology unique to

Japan, it may be difficult to secure the necessary

cooperation to integrate the Patriot system.However, in preparation for a contingency in

the Western Pacific, enhancing the combat

sustainment capabilities of SDF’s GSDF—making

it capable of stopping maritime invasions by an

aggressor nation on the frontlines and defending

Japan-U.S. bases from large-scale missile

attacks—should benefit the overall U.S. joint

forces. In addition, if the U.S. Army’s Patriot

system deployed in Japan during wartime were

damaged, the combined offensive and defensive

ground system would be able to fire the U.S.

Army’s remaining missiles, thereby improving

U.S.-Japan interoperability and resilience.

In other words, Japan’s combined offensive

and defensive system can be considered an

important asset for the U.S. military as well.

Japan may gain U.S. cooperation in this matter

by explaining that both parties stand to benefit.

Finally, the development of the combined offen -

sive and defensive ground system is not included

in the current Defense Buildup Program, meaning

that, at the moment, it lacks budgetary backing.

However, while using the Defense Buildup

Program as a basis, the Ministry of Defense

makes flexible budget requests depending on

the circumstances at the time. Furthermore,

expanding the SDF’s planned modifications to

the Patriot system to incorporate systems such

as the Type 12 SSM could result in more efficient

development.82 Explaining this and other advan -

tages clearly will significantly increase the proj -

ect’s chances of approval.

LIMITATIONS OF ADDRESSING

QUANTITATIVE THREATS THROUGH

ENHANCED LOW-END INTERCEPTION

MEASURES

It is possible that the development of non-ki -

netic interception means will take longer than

expected to complete and that, consequently,

deployment will be delayed. The SDF plans to

test prototypes of high-power lasers by FY 2025

and research and demonstration tests for high-

power microwave irradiation technology are

scheduled to continue until FY 2027.83 In both

cases, it is expected to take some time before

FOREIGN POLICY AT BROOKINGS 17mass production can commence, and develop -

ment may be further delayed depending on test

results. Until non-kinetic interception means are

established, efforts to gradually increase the

stockpile of kinetic interception means—namely,

low-end weapons and ammunition—are advis -

able. Additionally, as soon as signs of an enemy

invasion become apparent, a response can be

mounted by urgently procuring weapons and

ammunition from other countries and rapidly

training personnel.84

There is an additional risk that an invasion

might occur at a point when the supply of

low-end interception means is low. As previously

mentioned, the SDF’s short-range SAM arsenal is

undergoing partial replacement, and new short-

range SAMs and non-kinetic interception means

are under research and development. However,

just as the FrankenSAM intercepted the Shahed

UAV,85 the SDF’s legacy SAMs could intercept

UAVs of similar levels. By establishing opera -

tional procedures for legacy SAMs as a stopgap

measure until newer and more efficient intercep -

tion means are established, the situation can be

managed in the meantime.

Finally, investments in the aforementioned

MANPADS and anti-aircraft guns are not

currently included in the Defense Buildup

Program, which could make it difficult to

obtain project approval. As was the case for

the combined offensive and defensive ground

system, it will be necessary to carefully explain

these technologies’ necessity and effectiveness

in repelling anticipated large-scale UAV attacks.

It is also important to emphasize that these

weapons are generally inexpensive.

LIMITATIONS OF ESTABLISHING A

QUICK AND STABLE SUPPLY CHAIN

WITH 3D-PRINTING TECHNOLOGY

One of the foremost challenges of implementing

AM technology on a military-wide scale is

machine variability. Manufacturing variations can

and do occur in 3D printing, even when using the

same materials, data, maintenance protocols, and printer model—resolving this issue is essential

for stable production. Defects in weapons and

ammunition that result from machine variability

could put users in danger. For this reason, it is

not expected that AM technology will be capable

of efficiently and economically producing missiles

in the near future. However, by creating an AM

technology strategy early, investing proactively

in it, and standardizing technical verification

and certification processes and risk assessment

standards, the JMOD will be able to overcome

this issue, and the technological capabilities of

the defense industry will be enhanced as a result.

It is particularly important for the JMOD to set as

specific a goal as possible for the development of

AM technology (e.g., that 30% of parts of equip -

ment will be manufactured using AM technology

by 2040) and steadily make efforts toward real -

izing that goal. The publication of clear objectives

can also provide the impetus for industries to

switch to digital supply chains.

Another limitation of AM technology is that it is

currently able to produce only a limited range

of products. Equipment that includes electronic

components, for example, must be assembled

after the individual parts are printed. This means

that while equipment components, protec -

tive barriers, and decoys can be made solely

with 3D printers, complete products such as

missiles and drones cannot be created without

additional metal-processing equipment. This is

particularly true for drones. However, utilizing

vehicle-mounted 3D printers in tandem with

vehicle-mounted secondary processing facilities

would allow products that include electronic

components to be manufactured on-site. An

alternative solution would be to pre-install

secondary processing facilities at bases likely

to become front lines. Whatever the specific

circumstances are, a production system that

includes secondary processing equipment must

be established when incorporating AM tech -

nology.

Furthermore, because much of the AM supply

chain is digital, there is a risk of data theft or

tampering. Defense capabilities in this area can

18 STRENGTHENING JAPAN’S DEFENSE IN RESPONSE TO RUSSIA’S AGGRESSION AGAINST UKRAINEbe strengthened by establishing a cybersecurity

policy for AM technology and by sharing informa -

tion with existing cyber departments.

Budgetary demands, which are significant,

present another challenge for AM technology.

Since the JMOD must simultaneously invest in

many areas, it may be prevented from investing

sufficiently in AM technology. However, the

widespread use of AM technology could also

ameliorate financial strain by making it less

necessary to maintain parts stockpiles. It would

also prevent future cost increases due to the

sudden withdrawal of analog supply chains.

Investment in AM technology is an economical

measure in the long run.

Finally, much of the SDF’s latest equipment is

made in the United States, and Japan does not

have the authority to make design changes to

this equipment domestically, potentially limiting

the application of AM technology to domesti -

cally produced equipment. One reason for this is

that Japan does not yet have a strategy for AM

technology and has not reached the technical

level necessary to implement such a strategy.

This challenge can be overcome by Japan formu -

lating a strategy early and building a framework

for cooperation with the United States regarding

AM technology in the future. The Japan Ministry

of Defense could obtain cooperation from the

U.S. Department of Defense by explaining that

advances in Japanese AM technology could be

shared with Japan’s allies and would strengthen

U.S.-Japan interoperability and resilience.

Conclusion

The three strategies for enhancing the SDF’s

sustained combat capability discussed in this

paper—the development of combined offensive

and defensive ground systems, the enhancement

of low-end interception methods to address

quantitative threats, and the establishment of a

quick and stable supply system using 3D-printing

technology—are all measures that serve Japan’s

national interests as outlined in its 2022 National Security Strategy.86 They are key to peace and

stability in Japan and the Indo-Pacific region.

The combined offensive and defensive ground

systems are particularly desirable for their suit -

ability to situations in which resources are limited

and efficiency is paramount. They also constitute

a very achievable goal, as the technology for

such systems already exists.87 The enhance -

ment of low-end interception methods will have

a direct, positive effect on the SDF’s ability

to respond to large-scale, prolonged attacks.

Implementing AM technology will enhance the

sustainability of Japan’s warfighting operations

by stabilizing the supply chain and increasing

production capability. Moreover, Japan’s imple -

mentation of these initiatives would undoubtedly

benefit the United States, its ally. Developments

such as the ones outlined in this paper not only

enhance the SDF’s integrated operational capa -

bilities but also improve Japan-U.S. joint opera -

tional capabilities, significantly contributing to the

shared interest of deterring and responding to

unilateral attempts to change the status quo by

force.

Finally, a few additional factors warrant consid -

eration in this context. Japan has been facing a

rapid decline in birthrate and an aging population

for three decades—termed the “silent emer -

gency”—this is considered a serious national

issue. Japan’s working-age population (15-64

years old) was 75.6 million in 2020, but it is

projected to decrease to 45.35 million by 2070.88

The SDF is working to address the decline in

applicant numbers by extending the retirement

age of current SDF personnel89 and raising the

upper age limit of recruitment.90 The afore -

mentioned combined offensive and defensive

ground systems integrate three systems into

one, allowing for the consolidation of personnel

engaged in maintenance, supply, system capa -

bility enhancement, and project management. A

combined system eliminates the need to main -

tain separate unit formations, thereby enabling

better allocation of personnel resources. AM

technology, which can be operated with fewer

personnel, and which does not rely on individual

skill, could also compensate for the manpower

shortage in the analog supply chain.

FOREIGN POLICY AT BROOKINGS 19Furthermore, AM technology is already used in

the aerospace sector for manufacturing precision

components, and its significance is highlighted

by its application in many pieces of U.S. mili -

tary equipment, which is the result of focused

technological investment. Using AM technology

allows for rapid prototyping, which accelerates

innovation and has the potential to create game-

changing defense equipment. AM technology

can also be utilized for camouflage, concealment,

decoys, and hardening to enhance the viability

of critical assets. Therefore, it is crucial for the

JMOD to promptly develop, publish, and imple -

ment a strategy for this important technology,

as it can significantly enhance the SDF’s mission

capabilities. Additionally, initiative on the part

of government agencies like the JMOD will

lead to greater motivation for AM technology

investment across Japan’s industrial sector,

significantly contributing to the widespread adoption and technological advancement of

AM technology in the country. There are many

technological hurdles to be cleared—not only for

AM technology but also for non-kinetic means of

interception. However, investment in emerging

technologies itself constitutes a national defense

capability. If Japan were to give up such invest -

ments due to challenges and barriers, it would

never again be able to compete with other

countries in that area. That is why it is important

for the SDF not to give up easily on investing in

emerging technology.

In sum, these three proposed measures not only

contribute to strengthening Japan’s defense

capabilities but also bring benefits to its ally,

the United States, and hold great potential for

fostering the advancement of Japan’s entire

industrial sector and technological prowess.

Endnotes

1 “National Security Strategy of Japan,”

(Tokyo: Japan Ministry of Foreign Affairs,

December 2022), 9, https://www.mofa.

go.jp/fp/nsp/page1we_000081.html .

2 “Military and Security Developments

Involving the People’s Republic of China:

2023 Annual Report to Congress,”

(Washington, DC: U.S. Department

of Defense, 2023), 52, https://media.

defense.gov/2023/Oct/19/2003323409/-

1/-1/1/2023-MILITARY-AND-SECURITY-

DEVELOPMENTS-INVOLVING-THE-

PEOPLES-REPUBLIC-OF-CHINA.PDF .

3 Ibid., 62.

4 Ibid., 104.

5 Ibid., 186.

6 “Defense of Japan 2023,” (Tokyo: Japan

Ministry of Defense, 2023), 1, https://

www.mod.go.jp/en/publ/w_paper/wp2023/

DOJ2023_EN_Full.pdf .

7 Helen Davidson and Emma Graham-

Harrison, “Xi Jinping Opens Chinese

Communist Party Congress with Warning

for Taiwan,” The Guardian, October

16, 2022, https://www.theguardian.

com/world/2022/oct/16/xi-jin -

ping-speech-opens-china-communist-par -

ty-congress .

8 “U.S. Indo-Pacific Command Posture,”

statement of Admiral John C. Aquilino,

U.S. Navy Commander, U.S. Indo-Pacific

Command, to the 118th Congress, March

20, 2024, 3, https://www.congress.

gov/118/meeting/house/116960/

witnesses/HHRG-118-AS00-Wstate-

AquilinoJ-20240320.pdf .

9 Mark F. Cancian, Matthew Cancian, and

Eric Heginbotham, “The First Battle of the

Next War: Wargaming a Chinese Invasion

of Taiwan,” (Washington, DC: Center for Strategic and International Studies,

January 2023), 9, https://www.csis.org/

analysis/first-battle-next-war-wargam -

ing-chinese-invasion-taiwan .

10 Tetsuo Kodani, “ 研究レポート「日米同

盟」研究会　 FY2022-4 号2023年3月

30日台湾海峡有事シミュレーション：

概要と評価 ” [Research report of the

Japan-U.S. Alliance Study Group, FY

2022-2024 Edition, Japan-Taiwan Strait

Contingency Simulation], (Tokyo: Japan

Institute of International Affairs, March 20,

2023), http://www.jiia.or.jp/research-re -

port/2023/05/18/security-fy2022-04.pdf .

11 “Defense of Japan 2023,” 118.

12 Ibid., 103-4.

13 Ibid., 135.

14 “National Security Strategy, National

Defense Strategy, and Defense Buildup

Program (Outline),” (Tokyo: Japan Ministry

of Defense, September 2024), 2, https://

www.mod.go.jp/en/d_act/d_policy/pdf/

overview-202409.pdf .

15 “National Defense Strategy,” (Tokyo: Japan

Ministry of Defense, December 16, 2022),

8.

16 Meia Nouwens, “China’s New Information

Support Force: the People’s Liberation

Army Announced a Major Restructuring

of Its Information-Support Forces.

What Does It All Mean?” (London: The

International Institute for Strategic Studies,

May 3, 2024), https://www.iiss.org/

online-analysis/online-analysis/2024/05/

chinas-new-information-support-force/ .

17 “Defense of Japan 2024,” (Tokyo: Japan

Ministry of Defense, 2024), 63,74,86,

https://www.mod.go.jp/en/publ/w_paper/

index.html .

18 “Defense of Japan 2023,” 69.

19 Jakub Przetacznik with Simona Tarpova,

“Russia’s War on Ukraine: Timeline of

Cyber-Attacks,” (Brussels: European

Parliamentary Research Service, June

2022), https://www.europarl.europa.eu/

RegData/etudes/BRIE/2022/733549/EPRS_

BRI(2022)733549_EN.pdf .

20 “Defense of Japan 2023,” 7, 47.

21 Justin Bronk with Nick Reynolds and Jack

Watling, “The Russian Air War and Ukrainian

Requirements for Air Defence,” (London:

Royal United Services Institute, November

7, 2022), 7, 26, https://static.rusi.org/

SR-Russian-Air-War-Ukraine-web-final.pdf .

22 Ibid., 14.

23 “UK Says Bulk of Russian Forces 30 km

from the Center of Kyiv,” Reuters, February

26, 2022, https://www.reuters.com/world/

europe/uk-says-bulk-russian-forces-30-

km-centre-kyiv-2022-02-26/ .

24 “Defense of Japan 2023,” 35-36.

25 Andrew E. Krammer, “‘What’s the

Problem?’ Zelenskyy Challenges West

Over Hesitations,” The New York

Times , May 22, 2024, http://www.

nytimes.com/2024/05/21/world/europe/

ukraine-zelensky-interview.html .

26 Mariano Zafra et al., “Combat in Ukraine

is Changing Warfare,” Reuters, March 25,

2024, http://www.reuters.com/graphics/

UKRAINE-CRISIS/DRONES/dwpkeyjwkpm/ .

27 Emil Avdaliani, “Iran and Russia Enter a New

Level of Military Cooperation,” (Washington,

DC: The Henry L. Stimson Center, March

6, 2024), http://www.stimson.org/2024/

iran-and-russia-enter-a-new-level-of-mili -

tary-cooperation/ ; Kim Tong-Hyung, “South

Korean Defense Chief Says North Kirea Has

Supplied 7,000 Containers of Munitions to

Russia,” The Associated Press, March 18,

2024, https://apnews.com/article/north-ko -

rea-russia-arms-transfers-ukraine-a37b -

c290ed3ee59cfbbafdc2a994dc58 . 28 David Albright, Sarah Burkhard, and

the Good ISIS team, “Visible Progress

at Russia’s Shahed Drone Production

Site: Satellite Imagery Update and Call

for Action,” (Washington, DC: Institute

for Science and International Security,

November 13, 2023), https://isis-online.

org/isis-reports/detail/visible-progress-at-

russias-shahed-drone-production-site .

29 “Defense of Japan 2023,” 302, 310.

30 “Integrated Air and Missile Defense,” Japan

Ministry of Defense, https://www.mod.

go.jp/en/d_architecture/missile_defense/

index.html .

31 Ibid.; “Patriot Guidance Enhanced Missile,”

Raytheon, http://www.rtx.com/raytheon/

what-we-do/integrated-air-and-mis -

sile-defense/guidance-enhanced-missile .

32 “中距離地対空誘導弾の取得 ” [Acquisition

of medium-range surface-to-air guided

missiles], (Tokyo: Japan Ministry of

Defense), 5, http://www.mod.go.jp/j/policy/

hyouka/rev_suishin/r03/pdf/r03_ronten -

shiryou_01.pdf .

33 “基地防空用 SAMの技術的追認 ” [Technical

follow-up of surface-to-air missiles for

the base air defense], Japan Air Self-

Defense Force, https://www.mod.go.jp/

asdf/adtc/second5/third1/PDF/hizitudan/

kitibouei.pdf . See also “Defense Programs

and Budget of Japan: Overview of FY

2012 Budget,” (Tokyo: Japan Ministry of

Defense, 2012), 5, 24, https://www.mod.

go.jp/en/d_act/d_budget/pdf/231220.pdf .

34 “基地防空用地対空誘導弾 ” [Surface-to-air

guided missiles for the base air defense],

Japan Air Self-Defense Force, http://

www.mod.go.jp/asdf/equipment/other/

yuudoudan/ .

35 “Integrated Air and Missile Defense,” Japan

Ministry of Defense.

36 “移動式警戒管制レーダー等の配備候補地に

係る検討状況に関する説明会 ” [Briefing on

candidate sites for deployment of mobile

warning and control radar, etc.], (Tokyo:

Japan Ministry of Defense, July 20,

2023), 10, http://vill.kitadaito.okinawa,jp/

docs/2023072100018/file_contents/

setumei.pdf .

37 “装備” [Equipment], Japan Air Self-Defense

Force, http://www.mod.go.jp/asdf/equip -

ment/ .

38 “Progress and Budget in Fundamental

Reinforcement of Defense Capability:

Overview of FY 2024 Budget Request,”

(Tokyo: Japan Ministry of Defense), 49,

https://www.mod.go.jp/en/d_act/d_budget/

pdf/20240607a.pdf .

39 As referred to by the GSDF. The ASDF

uses the term “improved surface-to-air

missile for base air defense.” Hereafter, it

will be referred to uniformly as the “new

short-range SAM.” See “ 基地防空用地対

空誘導弾（改）及び新近距離地対空誘導弾 ”

[Surface-to-air guided missile (improved)

for base air defense and new short-range

surface-to-air guided missile], (Tokyo:

Japan Ministry of Defense), https://www.

mod.go.jp/j/approach/hyouka/rev_suishin/

r02/pdf/03-0008.pdf .

40 “令和３年度 政策評価書（事前の事業評価 )”

[FY 2021 policy evaluation report (prelim -

inary project evaluation)], 防衛装備庁プ

ロジェクト管理部事業監理官 [Acquisition,

Technology and Logistics Agency (ATLA),

Project Management Division], (Tokyo:

Japan Ministry of Defense, August 2021),

https://www.mod.go.jp/j/policy/hyouka/

seisaku/2021/pdf/jizen_01_honbun.pdf .

41 “防衛産業の実態-ご説明資料 ” [Briefing

material: facts about the defense industry],

防衛庁装備政策課 [Acquisition, Technology

and Logistics Agency], (Tokyo: Japan

Ministry of Defense, June 28, 2023), 6,

https://www.mod.go.jp/atla/soubiseisaku/

soubiseisakukaigishiryou/kentoukai01_

shiryo04.pdf .42 Jakub Przetacznik with Simona Tarpova,

“Russia’s War on Ukraine: Timeline of

Cyber-Attacks,” 2.

43 Justin Bronk with Nick Reynolds and Jack

Watling, “The Russian Air War,” 7.

44 Ibid., 7, 26.

45 William M. Arkin, “Exclusive: Russia’s Air

War in Ukraine is a Total Failure, New

Data Show,” Newsweek, May 25, 2022,

http://newsweek.com/exclusive-russias-

air-war-ukraine-total-failure-new-data-

show-1709388 .

46 Justin Bronk with Nick Reynolds and Jack

Watling, “The Russian Air War,” 7-8.

47 Mark F. Cancian, Matthew Cancian, and

Eric Heginbotham, “The First Battle of the

Next War.”

48 Justin Bronk with Nick Reynolds and Jack

Watling, “The Russian Air War,” 14.

49 “Defense Buildup Program,” (Tokyo:

Japan Ministry of Defense, December

16, 2022), 6-7, https://www.mod.go.jp/j/

policy/agenda/guideline/plan/pdf/program_

en.pdf .

50 Mariano Zafra et al., “Combat in Ukraine Is

Changing Warfare.”

51 Ibid.

52 Natasha Bertrand, “US Assesses Russia

Now in Possession of Iranian Drones,

Sources Say,” CNN, August 30, 2022,

https://edition.cnn.com/2022/08/29/poli -

tics/russia-iranian-drones/index.html .

53 Mariano Zafra et al., “Combat in Ukraine Is

Changing Warfare.”

54 David Albright, Sarah Burkhard, and the

Good ISIS team, “Visible Progress at

Russia’s Shahed Drone Production Site.”

55 The FrankenSAMs are systems that have

been developed from modified Soviet-era

missile launchers or radars that were

in Kyiv’s possession. See Kaitlin Lewis,

“What Is FrankenSAM? Ukraine Reports

First Successful Use of New Weapon,”

Newsweek, January 17, 2024, https://

www.newsweek.com/what-frankensam-

ukraine-reports-first-successful-use-new-

weapon-1861685 ; Justin Bronk with Nick

Reynolds and Jack Watling, “The Russian

Air War,” 34, 36.

56 Mariano Zafra et al., “Combat in Ukraine Is

Changing Warfare.”

57 “Minister Urges Ukrainians to Create

Drones for Army at Home,” The Kyiv

Independent, January 13, 2024, https://

kyivindependent.com/digital-transfor -

mation-minister-encourages-ukraini -

ans-to-create-drones-for-army-at-home/ .

58 Mariano Zafra et al., “Combat in Ukraine Is

Changing Warfare.”

59 “Defense of Japan 2023,” Japan Ministry

of Defense, 67, 71.

60 Jen Judson, “How Patriot Proved Itself

in Ukraine and Secured a Fresh Future,”

Defense News, April 9, 2024, https://

www.defensenews.com/land/2024/04/09/

how-patriot-proved-itself-in-ukraine-and-

secured-a-fresh-future/ .

61 “Defense Programs and Budget of Japan:

Overview of FY 2011 Budget,” 5, 24.

62 “Progress and Budget in Fundamental

Reinforcement” 14.

63 Jared Keller, “The Army Has Officially

Deployed Laser Weapons Overseas to

Combat Enemy Drones,” Military.com, April

24, 2024, http://www.military.com/daily-

news/2024/04/24/army-has-officially-de -

ployed-laser-weapons-overseas-com -

bat-enemy-drones.html?amp .

64 Ian Casey and Jonathan Beale,

“DragonFire: UK Laser Could Be Used

against Russian Drones on Ukraine Front

Line,” BBC News, April 12, 2024, https://

www.bbc.com/news/uk-68795603 . 65 “防衛力整備計画について ” [Outline of

Defense Buildup Program], (Tokyo: Japan

Ministry of Defense, December 2022), 20,

https://www.mod.go.jp/j/policy/agenda/

guideline/plan/pdf/plan_outline.pdf .

66 William M. Arkin, “Russia’s Air War in

Ukraine is a Total Failure.”

67 Natasha Bertrand, “US Assesses Russia

Now in Possession of Iranian Drones.”

68 Kim Tong-Hyung, “South Korean Defense

Chief Says North Korea Has Supplied 7,000

Containers of Munitions to Russia”; John

Hardie, “Russian Munitions Production

Higher but Still Insufficient,” Foundation

for Defense of Democracies, January

18, 2024, http://www.fdd.org/analysis/

op_eds/2024/01/18/russian-munitions-pro -

duction-higher-but-still-insufficient ; Mary

Ilyushina, “Russia Ramps up Weapons

Production, Using Mass Quantity to Outgun

Ukraine,” The Washington Post , April 19,

2024, https://www.washingtonpost.com/

world/2024/04/19/russia-weapons-pro -

duction-ukraine-war/ .

69 Karoun Demirjian, “Congress Abandons

Ukraine Aid Until Next Year as Border

Talks Continue,” The New York Times ,

December 19, 2023, http://www.nytimes.

com/2023/12/19/us/politics/senate-

ukraine-border.html ; Andrew E. Krammer,

“‘What’s the Problem?’ Zelensky Challenges

West Over Hesitations.”

70 “Russian Forces Advance in Ukraine’s

East,” Reuters, April 29, 2024, http://www.

reuters.com/world/europe/russian-forces-

advance-ukraines-east-2024-04-29 .

71 Patricia Zengerle and Richard Cowan, “US

Congress Passes Ukraine Aid after Months

of Delay,” Reuters, April 23, 2024, http://

www.reuters.com/world/us/long-awaited-

aid-ukraine-israel-taiwan-poised-pass-us-

congress-2024-04-23/ .

72 “Defense of Japan 2023,” Japan Ministry

of Defense, 461.

73 Malcolm Ramsay and Malcolm Wheatley,

“After the Disaster in Japan,” Automotive

Logistics, July 1, 2011, http://www.automo -

tivelogistics.media/after-the-disaster-in-

japan/7408.article .

74 “3D Models – 3D printable,” NASA, http://

nasa3d.arc.nasa.gov/models/printable .

75 “Biden Administration Celebrates Launch

of AM Forward and Calls on Congress

to Pass Bipartisan Innovation Act,”

The White House, May 6, 2022, http://

www.whitehouse.gov/briefing-room/

statements-releases/2022/05/06/fact-

sheet-biden-administration-celebrates-

launch-of-am-forward-and-calls-on-con -

gress-to-pass-bipartisan-innovation-act/ .

76 “Department of Defense Additive

Manufacturing Strategy,” (Washington, DC:

Office of the Under Secretary of Defense

for Research and Engineering, January

2021), https://www.cto.mil/wp-content/

uploads/2021/01/dod-additive-manufac -

turing-strategy.pdf .

77 William Kuchinski, “The F-22 Raptor Gets

Its First Metallic 3D-Printed Part,” SAE

International, January 24, 2019, http://

www.sae.org/news/2019/01/the-f-22-rap -

tor-gets-its-first-metallic-3d-printed-part ;

Lan Kim, “3D Printed Parts for the C-5M

Deliver New Capabilities,” United States Air

Force, March 12, 2023, http://www.af.mil/

News/Article-Display/Article/3321057/3d-

printed-parts-for-the-c-5m-deliver-new-

capabilities .

78 Nicholas Slayton, “Air Force Team Designs,

3D Prints, Launches New Drone in under

24 Hours,” Task & Purpose, May 4, 2024,

https://taskandpurpose.com/news/

air-force-designs-drone-24-hours/ .

79 Oliver Johnson, “SPEE3D Brings Metal Cold

Spray 3D Printing to Japan Ground Self-

Defense Force,” TCT Magazine , September

12, 2023, https://www.tctmagazine.com/

additive-manufacturing-3d-printing-news/

latest-additive-manufacturing-3d-print -ing-news/spee3d-brings-metal-cold-

spray-3d-printing-to-japan-ground-s/ .

80 Yushi Nishida, “ 航空自衛隊草創期の高射部隊

帰属問題についての考察 ” [Consideration of

the issue of the attachment of anti-aircraft

units to the Japan Air Self-Defense Force

in its early days], 安全保障研究第 2巻第2号

[Security Studies ] 2, no. 2 (March 2022):

157-73, https://www.nids.mod.go.jp/publi -

cation/security/pdf/2022/202203_08.pdf .

81 “Patriot,” Mitsubishi Heavy Industries,

https://www.mhi.com/jp/products/defense/

mim104_patriot.html .

82 “Defense Buildup Program,” 8.

83 Akira Yokoyama, “ 防衛力の抜本的強化を

踏まえた研究開発事業の取組 ” [Research

and development projects based on the

fundamental strengthening of defense

capabilities], 防衛装備庁技術戦略部技

術計画官 [Acquisition, Technology and

Logistics Agency (ATLA), Technology

Planning Division], (Tokyo: Japan Ministry

of Defense, March 2023), https://www.

mod.go.jp/atla/research/ats2022/pdf/

prog_policy_02.pdf .

84 Since a period of preparation is required

before an invasion can be initiated, and

because preparation activities can be

detected through intelligence, there is

sufficient time to respond. See also John

Culver, “How We Would Know When China

Is Preparing to Invade Taiwan,” Carnegie

Endowment for International Peace,

October 3, 2022, https://carnegieendow -

ment.org/2022/10/03/how-wewould-

know-when-china-is-preparing-to-invade-

taiwan-pub-88053 .

85 Kaitlin Lewis, “What Is FrankenSAM?”

86 “National Security Strategy of Japan.”

87 “The U.S. Army’s Typhon Strategic

Mid-Range Fires (SMRF) System,”

(Washington, DC: Congressional Research

Service, April 16, 2024), https://crsreports.

congress.gov/product/pdf/IF/IF12135 .

88 “Population Projections for Japan (2023

Revision): 2021 to 2070, Appendix:

Auxiliary Projections 2071 to 2120,” (Tokyo:

National Institute of Population and Social

Security Research, April 26, 2023), 4,

http://www.ipss.go.jp/pp-zenkoku/e/

zenkoku_e2023/pp2023e_Summary.pdf . 89 “Defense of Japan 2023,” 500.

90 “Defense of Japan 2022,” (Tokyo: Japan

Ministry of Defense, 2022), 417-18, https://

www.mod.go.jp/en/publ/w_paper/wp2022/

DOJ2022_Digest_EN.pdf .

About the author

Colonel Tetsuro Fujimoto of the Japan Air Self-Defense Force (JASDF) was a federal

executive fellow at the Brookings Institution. He is an air defense officer with experience

in operating the Patriot system. From 2020 to 2021, he served as the commander of the

Koradai sub-base in Fukuoka Prefecture, Japan, while concurrently holding the position of

commander of the 8th Fire Unit, 2nd Air Defense Missile Group, contributing to the strength -

ening of Japan’s missile defense posture. In addition, he has held multiple positions within

Japan’s Ministry of Defense, including roles in both the Joint Staff Office and the Air Staff

Office, where he was responsible for integrated air and missile defense (IAMD). Through these

assignments, he has contributed to strengthening Japan’s IAMD capabilities. He is a graduate

of the National Defense Academy and the JASDF’s Command and Staff Course.

Acknowledgments

The author would like to thank Michael O’Hanlon, Jeffrey Hornung, Derek Solen, Yoichiro Koga, Makoto

Minoya, Enora Rogers, David Blair, Wesley Martin, Robert Norris, Masataka Oguro, Takao Inoue, Yukihiro

Asao, and Aya Yano for their helpful comments and feedback on this paper. He would also like to thank

Adam Lammon for the editing of this paper and Rachel Slattery for layout.

Disclaimer

The opinions expressed here are the author’s alone and do not represent the position of the Japan Air

Self-Defense Force, the Japan Ministry of Defense, or the Japanese government.

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