U.S. Military Operations Against Iran: Munitions and Missile Defense

U.S. Military Operations Against Iran: Munitions and Missile Defense
March 12, 2026 (IN12668)

Congress has expressed interest in the status of the U.S. military's inventories of munitions (e.g., ammunition, bombs, missiles, torpedoes, anti-aircraft weapons, missile interceptors). Since the United States and Israel launched military operations against Iran on February 28, 2026, some Members of Congress have sought information on the stockpiles and availability of U.S. weapons from the Department of Defense (DOD, which is "using a secondary Department of War designation," under Executive Order 14347 dated September 5, 2025). Some Members have raised concerns about potential shortfalls in munitions, while other Members have said munitions are not an immediate concern. President Donald J. Trump has said U.S. munitions are "virtually unlimited." DOD officials have said sufficient munitions are available, while maintaining that the status of U.S. stocks is considered "an operational security matter." In these comments, officials have not differentiated between stocks of air-to-ground and air-to-air munitions versus missiles and missile interceptors.

U.S. Capabilities Expended in Operation Epic Fury

DOD has not made public the precise numbers of specific types of munitions expended in the conflict, as a matter of "operational security." Congress has held classified briefings with Administration officials on the conduct of operations. Publicly, on March 3, Admiral Brad Cooper, commander of U.S. Central Command (CENTCOM), said, "We've already struck nearly 2,000 targets with more than 2,000 munitions," and that Iran had launched more than 500 ballistic missiles and more than 2,000 drones, many of which the United States and regional partners have intercepted. On March 10, DOD officials said the U.S. military has struck more than 5,000 targets.

U.S. officials have identified some of the types of missiles and munitions used by U.S. forces in the operation. These have included precision-guided munitions (PGMs) like the Joint Direct Attack Munition (JDAM), as well as the Low-cost Unmanned Combat Attack System (LUCAS), a one-way attack drone. According to General Dan Caine, Chairman of the Joint Chiefs of Staff, as U.S. operations have targeted Iranian ballistic missile and other military capabilities, U.S. forces have shifted from "large deliberate strike packages using stand-off munitions at range outside an enemy's ability to shoot at us now into stand-in precision strikes overhead Iran." Some observers have raised concerns about the potential effects that the U.S.-Israeli operation may have on munitions inventories for other potential contingencies.

To counter Iranian ballistic missile threats, the United States has employed ballistic missile defense (BMD) systems, including the PATRIOT, Terminal High-Altitude Area Defense (THAAD), and BMD-capable destroyers. DOD has said its stockpile of PATRIOT interceptors "remains extremely strong." Before February 28, observers raised concerns about U.S. THAAD and destroyer-based interceptor inventory. In June 2025, the U.S. reportedly fired a quarter of its historical purchases of THAAD interceptors while defending Israel against Iranian strikes. The U.S. employed the ship-based Aegis BMD system in 2024 and 2025 to defend Israel against Iranian strikes and to counter Houthi attacks in the Red Sea. A media report indicated that DOD may be moving PATRIOT and THAAD components to CENTCOM from other theaters.

Iranian strikes on U.S. and partner military and civilian sites have included attacks by drones (uncrewed aircraft systems, UAS). On March 2, General Caine said the "threat from one-way attack [UAS] has remained persistent." According to Secretary of Defense Pete Hegseth (who is using "Secretary of War" as a "secondary title" under E.O. 14347), DOD has "pushed every counter UAS system possible forward sparing no expense or capability." These counter-UAS systems could include weapons designed specifically for countering drones, such as the Army's Coyote interceptor and the Air Force Advanced Precision Kill Weapon System (APKWS), as well as other air defense systems, like the Stinger missile and Counter-Rocket Artillery and Mortar (C-RAM) system.

Potential Considerations for Congress

Supplemental funds. Congress may consider whether or not to provide supplemental funds for operations in the Middle East. DOD is reportedly developing an emergency funding request that may total $50 billion. On March 10, DOD officials reportedly estimated that the first two days of the conflict cost $5.6 billion in munitions. Supplemental or emergency funds could support replenishment of stockpiles or invest directly in production capacity. Some observers have highlighted that supplemental funding alone may not provide a consistent demand signal for industry to independently invest in production capacity.

FY2027 appropriations. In FY2025 and FY2026, Congress took steps to increase munitions stockpiles and production by authorizing and appropriating funds and granting DOD multiyear procurement authorities. In congressional testimony, DOD officials have highlighted U.S. military operations and U.S. support for Ukraine as reasons for the greater demand for quantities of and production capacity for munitions. Congress may consider whether or not to increase funding for munitions in FY2027 appropriations and subsequent years.

Defense industrial base challenges. Congress has directed the Secretary of Defense to submit to Congress reports on the defense industrial base for munitions, and on U.S. munitions stockpiles and inventory requirements. Congress may consider consulting such reports to determine whether or not additional information may be required. Congress may also consider conducting oversight of issues relating to the U.S. military operations, such as the amount of time required to replenish the munitions expended and the ability of the U.S. industrial base to do so.

Counter-drone capabilities. Congress has expressed concern about the threats posed by one-way attack drones, including drones produced and used by Iran, and has provided DOD with funding and authorities related to acquiring and fielding counter-drone systems. Congress may consider assessing the status and scope of existing reporting requirements on DOD counter-drone systems to determine whether or not additional information may be required.

Tactical and strategic vulnerabilities. Congress may consider the potential vulnerabilities associated with shortages of certain munitions and reported damage to associated defense systems that may require months or years to replenish. In the near term, these vulnerabilities may include a narrowing of options for sustaining operations in Iran and sustaining U.S. allies. In the medium term, Congress may assess how depleted stockpiles may affect the U.S. ability to "erect a strong denial defense along the First Island Chain," in the Indo-Pacific as described in the 2026 National Defense Strategy.