US Joint Chiefs of Staff Chairman Dan Caine believes current US ammunition stockpiles could affect military operations in Iran and has warned President Donald Trump, according to the report published and updated on July 30, 2026.

A recent analysis by the Washington-based Center for Strategic and International Studies said the United States has used about one-third of its Patriot missile-defense system and roughly half of its THAAD interceptor missiles since the war with Iran began.

The organization 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 also estimated that US THAAD interceptor stocks declined from about 452 before the war to between 234 and 278 remaining.