The United States military used up nearly half of its Patriot interceptor missile stockpile during its seven-week campaign against Iran, according to an analysis by the Center for Strategic and International Studies (CSIS).
A report by Washington-based outlet The Hill highlighted significant depletion across several key munitions, citing the CSIS analysis, and raised concerns about Washington’s preparedness for a potential conflict with China.
According to the CSIS study released on Tuesday, US forces fired almost 50% of their Patriot missiles during the operation. More than half of Terminal High Altitude Area Defence (THAAD) interceptors were also used, alongside over 45% of Precision Strike Missiles (PrSMs), during the air and missile campaign in Iran.
The analysis further found that more than 20% of Joint Air-to-Surface Standoff Missiles (JASSMs), over 30% of SM-3 interceptors and at least 10% of SM-6 missiles were expended as part of Operation Epic Fury.
CSIS warned that rebuilding stockpiles — including Tomahawk cruise missiles and JASSMs — to pre-operation levels could take between one and four years. These weapons, it noted, would be vital in any future conflict in the Western Pacific.
“Even before the Iran war, stockpiles were deemed insufficient for a peer competitor fight. That shortfall is now even more acute and building stockpiles to levels adequate for a war with China will take additional time,” the report’s authors wrote.
While the US is still likely to retain enough munitions to continue operations against Iran, the remaining inventory would fall short in a confrontation with a major adversary such as China, the report added.
Amid these concerns, the United States Central Command (Centcom), which led the Iran campaign, said its forces are actively rebuilding capacity during the ceasefire. In a social media message, CENTCOM said its “forces remain ready”.
Speaking alongside US Defence Secretary Pete Hegseth, Centcom commander Admiral Brad Cooper said: “We are rearming. We’re retooling, and we’re adjusting our tactics, techniques and procedures.”
“There is no military in the world that adjusts like we do, and that’s exactly what we’re doing right now during the ceasefire,” he added.
The findings come as President Donald Trump earlier held talks with leading defence contractors in March, after which he said production of “exquisite class” weapons would be increased fourfold.
Responding to the report, Pentagon chief spokesperson Sean Parnell defended the military’s capabilities, telling The Hill that the US remains fully equipped.
“The US military is the most powerful in the world and has everything it needs to execute missions at the time and place of the President’s choosing,” he said.
“As Secretary [Pete] Hegseth has highlighted numerous times, it took less than 10% of American naval power to control traffic in and out of the Strait of Hormuz. Since President Trump took office, we have executed multiple successful operations across combatant commands while ensuring the US military possesses a deep arsenal of capabilities to protect our people and our interests,” Parnell said in a statement. “Attempts to alarm Americans over the Department’s munitions stockpiles are both ill-informed and dishonourable.”
Meanwhile, Pentagon comptroller Jules ‘Jay’ Hurst said officials are planning to expand multi-year munitions contracts to as long as seven years, aimed at strengthening supply chains and encouraging sustained investment. The move forms part of the administration’s proposed $1.5 trillion defence budget.
“Once Operation Epic Fury ends, the naval assets sent to the Middle East will return to the Pacific. Munitions inventories will start to recover, but restoring depleted stockpiles and then achieving the desired inventory levels will take many years,” the report’s authors, Mark F. Cancian and Chris H. Park, wrote.
