The U.S. military may have already used up half of its most expensive missiles, and it could take up to 4 years to rebuild its stockpiles

The U.S. has depleted its store of seven major types of missiles, intensifying concerns of a “near-term risk” it will run out of munitions for a future war.

The Pentagon has used at least 45% of its stockpile of Precision Strike Missiles; 50% of its Terminal High Altitude Area Defense (THAAD) interceptors inventory; and almost half of its stockpile of Patriot ballistic interceptor missiles—all within the first seven weeks of war with Iran, according to an analysis published this week by the Center for Strategic and International Studies (CSIS).

Though the U.S. has enough missiles to continue to fight in the Iran war without limitations, there is an increased risk of the U.S. military being insufficiently prepared for a future war in the Pacific, noted the report, authored by Mark Cancian, a retired U.S. Marine Corps colonel, and Chris Park, a CSIS research associate. Prior to the conflict in Iran, munitions stockpiles were already drained. CSIS estimated it would take one to four years to restock the seven major munitions to prewar levels.

“The diminished munitions stockpiles have created a near-term risk,” the report said. “A war against a capable peer competitor like China will consume munitions at greater rates than in this war. Prewar invent...