MAY 27, 2026
CSIS analysis finds U.S. needs at least three years to replenish advanced weapons stockpiles depleted in Iran war
A new analysis from the Center for Strategic and International Studies, released Wednesday, found that U.S. military contractors need at least three years to replenish stockpiles of Tomahawk cruise missiles, Patriot interceptors, and THAAD interceptors used heavily in the Iran war. The report warned that depleted inventories have created "a window of vulnerability for a potential Western Pacific conflict," even as the U.S. is assessed to have enough munitions for any remaining scenario in the Iran war itself. The findings were released against the backdrop of a $1.5 trillion defense budget proposal for 2027 under the Trump administration.
The CSIS report, co-authored by retired Marine colonel and senior adviser Mark Cancian and research associate Chris H. Park, estimates that fully replenishing Tomahawk cruise missiles — more than 1,000 of which were fired at Iran — could take until late 2030 or early 2031. Patriot interceptors, with between 1,060 and 1,430 used during the war, are projected to be replenished by mid-2029, while replacing as many as 290 THAAD interceptors could take until the end of 2029.
The report attributed the shortage partly to post-Cold War procurement assumptions. Cancian said that after the fall of the Soviet Union in 1991, the U.S. assumed future wars would be short and regional, leading to low order volumes and a small manufacturing footprint among contractors. Russia's war with Ukraine revised that thinking, but Cancian told the AP that "it just takes time to build inventories," given complex supply chains and novel components. He also said the Biden administration deserved credit for initiating conversations with industry and beginning production ramp-ups, while noting the Trump administration has significantly increased funding.
The Trump administration has disputed the severity of the vulnerability. Defense Secretary Pete Hegseth told lawmakers he takes "issue with the characterization that munitions are depleted in a public forum," saying the military has "all the munitions needed to execute what we need to execute." Chief Pentagon spokesman Sean Parnell said the military "has everything it needs to execute at the time and place of the President's choosing." Hegseth has also said replenishment could take "months and years … depending on the weapon system," and has pushed contractors to double or even triple production capacity.