Escalation of the Israel-Iran Conflict

Overview

In October 2024, Iran and Israel exchanged attacks for the second time this year (see Figure 1 and Figure 2), after doing so in April. This resumption of direct conflict comes a year after Hamas (an Iranian ally) led attacks from the Gaza Strip against Israel. Beyond Gaza and the West Bank, hostilities between Israel and Iran-supported groups (the self-proclaimed "axis of resistance") have flared in Lebanon, Yemen and the Red Sea, Iraq, and Syria. U.S. forces and international vessels have also come under fire from Iranian-supported groups. While the Biden Administration has repeatedly supported Israel's right to self-defense, it also has sought to de-escalate tensions. Beyond the parties themselves, Israel-Iran escalation could have wide-ranging implications for a host of issues, including energy markets, nuclear proliferation, and U.S. global force posture. After Israel's October 26 retaliation to Iran's October 1 attack, a senior U.S. official said that this round of direct Israel-Iran fire should be complete, and that U.S. forces were ready to help in Israel's defense if Iran responds. Lawmakers may take varying stances on possible escalation or de-escalation in the Middle East and efforts to support, restrain, or oppose the operations of Israel and other key regional actors.

Figure 1. Reported Iranian Strikes on Israel (October 1, 2024)

Figure 2. Reported Israeli Strikes on Iran (October 26, 2024)

Notes: Israel reportedly struck air defense sites at Iranian energy facilities rather than the facilities themselves. When the attacks began, it was October 25 in the United States.

On October 1, Iran launched some 180 ballistic missiles at Israel in retaliation for killings it attributed to Israel of key Iranian, Hezbollah, and Hamas leaders. As during Iran's April barrage, the United States, United Kingdom, and France reportedly assisted in Israel's defense (and Jordan responded to projectiles that entered its airspace), and Israel reported no fatalities. Open sources indicated that areas in and around Israeli bases may have sustained more damage in October than in April. The October barrage featured more ballistic missiles, and Iran reportedly did not warn the United States in advance.

As expectations of an Israeli counterstrike mounted during October, President Joe Biden and U.S. officials consulted with Israeli counterparts regarding their planned response, openly advising them to avoid targeting sites related to Iran's nuclear program or oil industry, and—according to one Israeli journalist—possibly offering some material assistance if Israel exercised restraint. Some Arab Gulf leaders may have also harbored worries about the Israeli response given apparent Iranian warnings that Iran would target their countries if Israel used Gulf states' territory or airspace in its operations. In mid-October, U.S. officials directed the deployment of a Terminal High Altitude Area Defense (THAAD) battery to Israel—along with about 100 U.S. troops to operate it—to supplement other movements of U.S. forces expressly intended to bolster Israel's defenses, protect U.S. citizens and forces, and deter broader regional conflict. One media report around the same time said that continued missile attacks from Iran and its allies could lead to a shortage of Israeli air defense interceptors and stretch U.S. supply chain capabilities.

Israel's October 26 attack reportedly transited Syrian and Iraqi airspace, featured dozens of U.S.-origin aircraft, and targeted Iranian air defenses (including Russian-origin S-300 systems), military bases, drone and missile manufacturing facilities, and launch sites. Reportedly, four Iranian soldiers and a civilian were killed. Some sources have speculated about possible U.S.-Israel coordination or intelligence sharing in relation to the Israeli strike (Israeli Prime Minister Benjamin Netanyahu thanked the United States for "close coordination and assistance"; a senior U.S. official said "the United States was not a participant.") By targeting Iran's air defense systems, Israel might more easily strike Iranian nuclear and energy infrastructure in potential future attacks. Saudi Arabia and the United Arab Emirates condemned the "military targeting of" Iran and called for de-escalation.

While Iran said after Israel's attack that it has a right and obligation to defend itself against foreign acts of aggression, some reports suggest it may not opt to respond. Many analysts acknowledge Israeli military superiority, and Israel reportedly warned Iran that any further attack on Israel would trigger more significant retaliation.

Regional Assessment and Possible U.S. Policy Implications

Israel-Iran escalation occurs at a potential inflection point for the region. Israel may be pursuing an opportunity it perceives to improve its national security and regional position by degrading the capabilities, supply lines, and cohesion of Iran and its partners. How Israeli tactical successes might affect long-term outcomes remains uncertain. Questions that may influence Israeli and Iranian decisions on escalation or de-escalation under various circumstances include

• What political incentives or disincentives might Israeli or Iranian leaders have to weaken the other? What military consequences might result from further direct conflict or escalation elsewhere in the region (including Gaza and Lebanon)?
• What are potential implications of pursuing de-escalation and/or diplomatic deals to pause or end fighting? How might showing restraint affect Israel's or Iran's credibility vis-à-vis partners and adversaries, or impact the window of opportunity for either of them to employ certain military, economic, or diplomatic options?

Some analysts have argued that Iran might restart its nuclear weapons program, which the regime had halted in 2003. Some assessments indicate that Israeli actions over the past three months may have significantly reduced Iran's ability to deter or intimidate Israel via its missiles and allied militias.

In that context, future U.S. policy debate could focus on which military, economic, and diplomatic options are best-suited to deliver priority outcomes, which could include

• minimizing the regional influence of Iran, Russia, and the People's Republic of China;
• decreasing threats to U.S. forces/citizens and key U.S. partners (including Israel, Jordan, Egypt, and Arab Gulf states);
• avoiding nuclear proliferation; and
• bolstering security via Israel-Arab state relations.

Issues for Congress

In assessing potential legislative options and conducting oversight, Congress may consider the following.

U.S. Direct Military Support for Israel and Other Regional Partners

When contemplating the movement and use of military assets and personnel to and within the region, and associated authorizations or appropriations, U.S. officials and lawmakers might debate potential impacts on stated U.S. interests, which include, for example, potential regional de-escalation and nonproliferation, as well as the protection of U.S. forces, U.S. citizens, and global energy commerce.

U.S. Security Assistance for Israel

When weighing the timing, nature, and volume of arms shipments to Israel, Congress and the Biden Administration may consider the nature of Israeli operations, their impact on civilians, the extent to which they may or may not advance U.S. interests, U.S. supply chain capacity, and Israel's defense capabilities and current stockpiles. Since the outbreak of regional conflict in October 2023, some Members of Congress have differed with one another and the Administration on the nature and timing of arms exports to Israel, with some Members advocating greater scrutiny or conditions, and others calling for the Administration to expedite Israeli requests.

Impacts of Conflict or Sanctions on Iran and Global Energy Prices

Questions persist regarding the possible impacts of conflict, or increased U.S. and multilateral sanctions or sanctions enforcement, on Iran's energy sector, nuclear program, and military capabilities. Such impacts may in turn affect regional and global diplomatic, security, and economic outcomes—including worldwide energy prices and Iran's targeting of or support for other regional actors. On October 11, the Administration announced expanded sanctions against Iran's oil industry, including a "ghost fleet" accused of enabling exports.