The Washington-based Center for Strategic and International Studies said the United States has used about one-third of its Patriot missile-defense system interceptors and roughly half of its THAAD interceptor missiles since the war with Iran began. The assessment was reported on July 30, 2026.

CSIS estimated that the United States had about 2,330 Patriot interceptors before the war, with the current total falling to between 759 and 827. It said the US had approximately 452 THAAD interceptors before the conflict and now has between 234 and 278 remaining.

The institution said its estimates were based on US Department of Defense fiscal 2027 budget documents and publicly available information. CSIS warned that if conflict with Iran resumes, the United States would have to manage the situation with fewer interceptors. It said this could increase risks to air defense and compel the United States and its allies to take greater strategic risks in using interceptors.