The seven-week Iran war, currently on pause due to an extended ceasefire, has raised alarm in Washington over the question of how fast the US has burned through its missile interceptor stockpile.

The two-week ceasefire, having just been extended, provided an opportunity for both sides to restock and regroup. A fresh analysis from the Washington-based Center for Strategic and International Studies (CSIS) finds the US military tore through nearly half its Patriot interceptor inventory while heavily draining multiple other critical missile stockpiles.

US Army file image

According to CSIS, the Pentagon burned through almost 50% of its Patriot missiles, more than half of its Terminal High Altitude Area Defense (THAAD) systems – designed to counter short, medium, and intermediate-range threats – and over 45% of its Precision Strike Missiles (PrSMs) during the Iran air and missile campaign.

And the hangover won’t be short given that replenishing key munitions – including Tomahawks and JASSMs – back to levels before Trump’s latest war of choice in the Middle East could take anywhere from one to four years.

Below is a key line from the fresh CSIS report:

The Trump administration recently announced a series of agreements with industry to boost production and put missile inventories on a “wartime footing.” The large quantities of munitions in the president’s FY 2027 budget request further underscore the urgency of rebuilding and expanding the inventory. Near-term deliveries, however, are relatively low because of small orders in the past. Even if Congress appropriates the requested FY 2027 funds, it will take years for these missiles to be delivered.

Of course, some of these systems were already removed from the Asia-Pacific area, where the US military has an eye on China. These systems are of course central to any future showdown 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 CSIS report’s authors wrote.

However, the Pentagon’s line has consistently been that the Untied States military remains the  most “powerful in the world and has everything it needs to execute at the time and place of the President’s choosing.”

The reality is that in the opening days of Operation Epic Fury, the US seemed underprepared for the ferocity of the Iranian response. At least 13 American bases in the region were hit and damaged, to the point that US forces across the region had to be moved back, and energy sites across the Gulf were pummeled and suffered billions of dollars in damage.

US interceptors worked in overdrive drying to protect sensitive Gulf facilities and bases, as dozens of inbound Iranian drones and missiles were a daily thing back in March into early April before the ceasefire took effect.