Defense Primer: Commanding U.S. Military Operations

Military operations, both in peacetime and in war, are an inherently complex undertaking. One key to success, therefore, is a clear, unified chain of command. This enables senior leaders in the U.S. government—in particular, the President and the Secretary of Defense—to command and control military forces around the world.

A (Very) Brief History of the Chain of Command

The way the United States commands and controls its forces is in large part a product of an inherent tension between improving the effectiveness of U.S. forces, on the one hand, and preserving civilian control of the military, on the other. The experience of World War II convinced President Truman, among others, that a greater degree of coordination and integration between the U.S. military services was necessary to improve the conduct of military operations. Yet there was concern at the time that integrating these institutions might result in an overly powerful military staff element that could threaten the principle of civilian control of U.S. forces.

The resulting compromise was to create a Joint Chiefs of Staff (JCS), comprising all the military service chiefs, and headed by a Chairman serving as an advisory body only. As a corporate body, the JCS was specifically not designed to exercise command; the Chairman of the Joint Chiefs of Staff (CJCS) had no command authority. The JCS did, however, have responsibility for establishing "unified combatant commands," which were charged with executing military operations in different parts of the world by combining the capabilities of two or more military services. Different service chiefs were assigned executive and administrative responsibilities for these combatant commands, which gave them a mechanism through which they could influence ongoing military operations. By 1953, the authority to establish Combatant Commands (COCOMs) was assigned to the Secretary of Defense, although the relative ambiguity of the chain of command remained a feature of Department of Defense (DOD) operations until 1986.

Perceived shortcomings in the U.S. chain of command led to demonstrable failures during several incidents in the late 1970s and early 1980s. The military services, in the view of many observers, failed to effectively plan or conduct operations jointly due to confusion over whether the military services or unified combatant commanders were ultimately in charge of operations. These incidents included the 1983 operation in Grenada; the 1980 Iranian hostage rescue attempt (officially "Operation Eagle Claw" but often called "Desert One"); and the 1983 bombing of the Marine Barracks in Beirut, Lebanon. In 1986, Congress passed the Goldwater-Nichols Defense Reform Act (P.L. 99-433), which mandated clarifications to the chain of command. The current command and control architecture for DOD is a product of these congressionally mandated changes.

The Chain of Command

Title 10 U.S.C. §162 specifies that the chain of command for military operations goes from the President, to the Secretary of Defense, to Commanders of Combatant Commands. The Chairman of the Joint Chiefs of Staff acts as an intermediary, transmitting orders between the Secretary of Defense and the Commanders of Combatant Commands. Each Combatant Commander is a four-star Flag or General Officer, whose appointment is confirmed by the Senate.

Unified Command Plan (UCP)

The UCP is a classified executive branch document that articulates how DOD assigns responsibility for different missions and areas of the world. It is prepared by the Chairman of the Joint Chiefs of Staff every two years and approved by the President. Each UCP sets forth basic guidance to all unified combatant commanders; establishes their missions, responsibilities, and force structure; delineates the general geographical area of responsibility for geographic combatant commanders; and specifies functional responsibilities for functional combatant commanders. Congress is not included in this review process but does have visibility into issues affecting UCP development. It is through the UCP that DOD develops its global map of areas of responsibilities for its Combatant Commanders, reflected in Figure 1.

Figure 1. Combatant Commanders' Area of Responsibility

Source: Association of the U.S. Army, "The Army on Point: A Detailed Summary of Current Operations and Responsibilities (2022)," August 5, 2022. Accessed November 28, 2022, https://www.ausa.org/publications/army-point-detailed-summary-current-operations-and-responsibilities-2022.

The Combatant Commands Today

A COCOM is a military command with broad continuing missions under a single commander and composed of significant assigned components of two or more military departments. There are currently eleven Combatant Commands. The COCOMs have responsibility for the military's operations in their respective areas.

There are seven regionally focused COCOMS, which operate in clearly delineated areas of operation and have a distinctive regional military focus:

• U.S. Africa Command (USAFRICOM), responsible for sub-Saharan Africa. It is located at Kelley Barracks, Stuttgart, Germany.
• U.S. European Command (USEUCOM), responsible for all of Europe, large portions of Central Asia, parts of the Middle East, and the Arctic and Atlantic Oceans. It is located at Patch Barracks, Stuttgart, Germany.
• U.S. Central Command (USCENTCOM), responsible for most of the Middle East, parts of Northern Africa and west Asia, and part of the Indian Ocean. It is located at MacDill Air Force Base, FL.
• U.S. Northern Command (USNORTHCOM), responsible for the defense of the continental United States and coordination of security and military relationships with Canada and Mexico. It is located at Peterson Air Force Base, CO.
• U.S. Southern Command (USSOUTHCOM), responsible for Central America, South America, and the Caribbean. It is located in Miami, FL.
• U.S. Indo-Pacific Command (USINDOPACOM), responsible for the Pacific Ocean, Southwest Asia, Australia, south Asia, and part of the Indian Ocean. It shares responsibility for Alaska with U.S. Northern Command. It is located at Camp H.M. Smith, HI.
• U.S. Space Command (USSPACECOM), provides space combat power for the Joint/Combined force and develops joint warfighters in, from, and through the space domain. It is located at Peterson Air Force Base, CO.

There are also four "functional" COCOMs, which operate worldwide across geographic boundaries and provide unique capabilities to geographic combatant commands and the services:

• U.S. Strategic Command (USSTRATCOM), responsible for deterring attacks on the United States and its allies and directing the use of U.S. strategic forces. It is located at Offutt Air Force Base, NE.
• U.S. Special Operations Command (USSOCOM), which provides special forces, counter-paramilitary, counter-narcotics, guerilla, psychological warfare, civil education, and insurgency capabilities. It is located at MacDill Air Force Base, FL.
• U.S. Transportation Command (USTRANSCOM), which provides air, land and sea transportation to different components of DOD. It is located at Scott Air Force Base, IL.
• U.S. Cyber Command (USCYBERCOM) directs, synchronizes, and coordinates cyberspace planning and operations to defend and advance national interests in collaboration with domestic and international partners. It is located at Fort George G. Meade, MD.

Service Component Commands

Service Component Commands consist of organizations, individuals, units, detachments, and/or support forces that belong to a particular military service but are assigned to a Combatant Commander. As an example, U.S. Army Central (USARCENT), U.S. Naval Forces Central Command (USNAVCENT), and U.S. Air Forces Central Command (USAFCENT) are all service component commands to U.S. Central Command (USCENTCOM). These components are subordinate to their respective Combatant Commanders.

The Laws Governing COCOMs

COCOMs are governed by the provisions contained in Sections 161 through 167b of Title10, Armed Forces, U.S. Code. These sections address the following provisions:

• Section 161: The establishment of COCOMs;
• Section 162: Chain of command and assignment of forces for COCOMs;
• Section 163: Role of the CJCS;
• Section 164: Assignment and powers and duties of commanders of COCOMs;
• Section 165: Administration and support of COCOMs;
• Section 166: COCOM budget proposals;
• Section 166a: Funding COCOMs through the CJCS;
• Section 166b: Funding for combating terrorism readiness initiatives;
• Section 167: Unified COCOMs for special operations forces; and
• Section 167b: Unified COCOM for cyber operations.

Kathleen J. McInnis was the original author of this product.