U.S. will need years to replenish advanced weapons stockpiles depleted in Iran campaign, analysis finds

The CSIS analysis, co-authored by retired Marine colonel and senior adviser Mark Cancian and research associate Chris H. Park, draws on publicly available Pentagon budget materials to estimate production timelines for the classified munitions inventories. The report concluded that while the U.S. has enough munitions for "any plausible scenario in the Iran war," rebuilding stockpiles to pre-war and eventually war-planner-desired levels will take several years.

For individual systems, CSIS estimates that replenishing the 1,000-plus Tomahawk cruise missiles fired during the campaign could take until late 2030, given that fewer than 200 were being produced annually before recent ramp-up efforts. Replacing as many as 290 THAAD interceptors could take until the end of 2029, and replenishing more than 1,000 Patriot interceptors should wrap up around mid-2029. A January Pentagon deal with Lockheed Martin aims to quadruple THAAD production from 96 to 400 units annually, according to the Washington Examiner.

The Trump administration's proposed $1.5 trillion defense budget for fiscal year 2027 — described by both sources as historic — significantly accelerates spending on high-end munitions. Defense Secretary Pete Hegseth told lawmakers the department would help manufacturers double or triple their production capacities. However, the CSIS report stated that "the problem today isn't money; it's time," noting that expanding production requires building out supply chains and manufacturing infrastructure for complex systems. Cancian told the Washington Examiner that "a sustained commitment that continues not just in the Trump administration but beyond that" will be necessary.