U.S. military contractors will need at least three years to replenish stockpiles of three key weapons systems heavily used during the Iran war, according to an analysis released Wednesday by the Center for Strategic and International Studies. The weapons include Tomahawk cruise missiles, Patriot interceptors, and Terminal High Altitude Area Defense (THAAD) systems.

The think tank report found that while the United States has sufficient munitions for the Iran conflict, the depleted inventories have created vulnerability concerns for potential future conflicts, particularly in the Western Pacific. The analysis comes as China has stated goals of ensuring its military can take Taiwan by force if necessary by 2027, though experts view this more as aspirational than a firm deadline.

The U.S. fired over 1,000 Tomahawk missiles at Iran and could need until late 2030 to fully replenish prewar inventory levels, the report estimates. Replacing up to 290 THAAD interceptors that shot down Iranian drones and missiles could take until the end of 2029, while replenishing more than 1,000 Patriot interceptors should complete by mid-2029. Current production rates remain relatively low due to historically small orders following the Cold War's end.

The Trump administration's proposed $1.5 trillion defense budget for 2027 significantly accelerates spending on advanced munitions, building on efforts begun during the Biden administration. However, the report notes that "the problem today isn't money; it's time," as expanding production capacity for complex weapons systems requires years to implement across supply chains and subcontractors.

Defense Secretary Pete Hegseth has pushed contractors to speed production, telling lawmakers that military spending under Trump will help manufacturers double or triple their capacities. Chief Pentagon spokesman Sean Parnell stated the military "has everything it needs to execute at the time and place of the President's choosing." Major defense contractors including RTX and Lockheed Martin have announced multi-billion dollar investments to boost production facilities.

The munitions shortage stems from post-Cold War assumptions that future conflicts would be short and regional, requiring fewer advanced weapons. Russia's prolonged war with Ukraine demonstrated that modern conflicts can require sustained, deep inventories of sophisticated munitions, prompting military strategists to reassess requirements for potential Pacific theater conflicts.