The U.S. military’s stockpile of Patriot interceptors has decreased by at least 65% since the start of hostilities with Iran, according to a July 27 report from the Center for Strategic and International Studies (CSIS). The stockpile fell from approximately 2,330 interceptors before the conflict to between 759 and 827 after a recent exchange of strikes in early July. Terminal High Altitude Area Defense (THAAD) interceptors also declined by at least 38%, dropping from 452 to 232–262 during the same period, though some replenishment efforts have since occurred.
The CSIS report highlights that diminished stockpiles may force the U.S. and its allies to take greater risks with missile intercepts. Mark Cancian, a retired Marine colonel and CSIS adviser who co-authored the report, noted that Patriot and THAAD systems remain critical for ballistic missile defense, as naval-based interceptors are often too distant to respond effectively. The Pentagon has not publicly confirmed these figures but has acknowledged efforts to expand production capacity for critical munitions.
Operation Epic Fury, launched by President Donald Trump on February 28, has been a key driver of interceptor depletion. U.S. forces have used these systems to defend regional bases from Iranian retaliatory strikes. While the Pentagon has not disclosed the total number of targets struck since the April ceasefire, Trump stated last week that the U.S. has "massive amounts" of munitions, with production and shipping efforts underway to address shortages. Defense contractors have also been pressed to accelerate resupply.
What are Patriot and THAAD missiles?
Both systems are central to the U.S. layered missile defense strategy. The THAAD is designed to intercept short and medium-range ballistic missiles at high altitudes, while the Patriot system—equipped with PAC-3 interceptors—provides broader air defense against aircraft, cruise missiles, and ballistic threats. Together, they form a critical shield in conflicts such as those in Ukraine and West Asia, where ballistic missile threats are prevalent.
Political and Strategic Responses
Democratic Senator Chris Murphy of Connecticut criticized the Trump administration, stating on NBC’s Meet the Press that "Donald Trump has lost this war" and that America is weaker as a result. Murphy pledged Democratic support for funding to replenish munitions but warned that the conflict has emboldened Russia and China. Republican Senator Lindsey Graham introduced the Lindsey O. Graham Sanctioning Russia and Iran Act, which proposes tariffs of up to 100% on major importers of Russian oil and gas, including China and India, while strengthening sanctions on Iran.
Long-Term Implications
The Pentagon has acknowledged that replenishing stockpiles will take years, depending on the system. Some munitions used in the Iran conflict overlap with those needed for potential future conflicts, such as a Taiwan scenario, where U.S. forces would rely on similar air defense systems. Joe Costello, a defense analyst, noted that there are "sizable overlaps" in the systems required for both theaters, raising questions about the military’s preparedness for a peer adversary conflict.
Pentagon Denies Critical Shortfalls
The Trump administration has disputed reports of diminished stockpiles, with Trump and Pentagon spokespeople asserting that production is scaling up and that the military has sufficient resources. However, CSIS’s data and independent analyses suggest that while replenishment efforts are underway, the current stockpiles remain significantly reduced compared to pre-conflict levels.