By Zachary Cohen, Jim Sciutto, Haley Britzky, CNN(CNN) — The US military has exhausted nearly 80% of its interceptors for a key missile defense system as senior US military commanders are warning that the Pentagon’s munitions stockpile is “dangerously low,” according to multiple sources familiar with the matter. Stockpiles of key air defense systems have been particularly depleted during the war with Iran. The US military has burned through nearly four-fifths of its THAAD missile inventory compared to pre-war numbers and roughly half of its Patriot interceptors since the start of the war, according to two sources familiar with the latest inventory report. “The lack of interceptors means that conventional attacks can backfire if the suicide drones start making it through in-masse,” one of the sources familiar with the stockpile concerns said. CNN reported in April that the US military had used nearly 30% of its Tomahawks during the early stages of the war.