Is the US Running Out of Weapons? Iran War Leaves Pentagon With Munitions Shortfall and $33.4 Billion Bill

The U.S. military is facing strategic ammunition shortfalls after its four-month campaign against Iran, according to the Pentagon inspector general, which said the expenditure of munitions during Operation Epic Fury exposed weaknesses in the U.S. defense industrial base.

The report estimated the cost of the operation at $33.4 billion through June 29, including $22.3 billion in expended munitions.

The findings were contained in the first Lead Inspector General report to Congress on Operation Epic Fury. The report covers the period through June 30 and was released Sept. 14 by the Department of War Office of Inspector General. It was prepared under the quarterly reporting requirements of the Inspector General Act.

The report outlines the supply shortcomings and challenges in the ability to increase production rapidly enough to replace some of the munitions expended during the campaign.

Pentagon Breaks Down Iran Campaign Costs

The Pentagon’s $33.4 billion estimate consists of $7.4 billion in cumulative obligations, $22.3 billion for expended munitions and $3.7 billion in equipment losses, according to the inspector general’s report. Infrastructure repair costs are not included in that figure.

The scale of the munitions bill represents the value of weapons consumed during the operation rather than simply the Pentagon’s broader operating expenses.

The White House had sought additional funding from Congress as the war continued. On June 24, the administration submitted an $87.6 billion supplemental funding request, including $67.1 billion for the Pentagon. The request included $21 billion for munitions and $17.3 billion for operational costs.

The munitions request therefore provides an earlier indication of the scale of the replenishment requirement, although the supplemental package also covered expenses unrelated to the Iran campaign.

Industrial Base Faces Replenishment Constraints

The inspector general’s report cited the Office of the Under Secretary of War for Acquisition and Sustainment as finding that munitions expenditure “has resulted in strategic inventory shortfalls and revealed industrial base bottlenecks for munitions resupply.”

The report said the defense industrial base requires significant lead time to expand production capacity. It found challenges associated with high-quality solid rocket motors, high-quality explosives and propellant, and skilled manufacturing labor.

The Pentagon said it is “working to streamline procurement processes and production lead times, and to stockpile critical materials, components, and selected munitions to respond rapidly to a contingency.”

The Pentagon officials have repeatedly stated over the years that it would be necessary to boost U.S. weapons manufacturing in the event of a major war. In 2024, then-Deputy Defense Secretary Kathleen Hicks stated that the U.S. was spending billions of dollars on industrial base infrastructure, multi-year procurement of critical munitions, and more.

Defense Secretary Pete Hegseth has also made expansion of weapons production a priority. In a 2025 speech, he said the Pentagon was establishing a munitions war room and seeking to strengthen the U.S. defense industrial base.

Aircraft Losses Add to the Cost

The inspector general’s report also documented losses and damage to U.S. military aircraft during Operation Epic Fury.

The report listed four F-15 aircraft destroyed, one F-35 damaged, seven KC-135 tanker aircraft damaged, and as many as 30 MQ-9 Reaper drones destroyed.

The equipment losses were valued at $3.7 billion at replacement cost in the Pentagon’s overall estimate. The figure is separate from the $22.3 billion attributed to expended munitions.

The inspector general’s report said Iranian strikes damaged or destroyed hundreds of buildings and structures at U.S. bases across the region. The infrastructure costs were not included in the $33.4 billion estimate because the full cost and scope of repairs had not been determined.

Funding Is Now Central to Rebuilding Stockpiles

In the June supplemental request for additional funding, the administration already identified replenishment of weapons inventories as a budget priority prior to the inspector general’s report.

In the same $67.1 billion Pentagon request, the White House asked for $21 billion to be dedicated to munitions. Total supplemental requests amounted to $87.6 billion, including requests for fuel, readiness, cybersecurity and other programs.

In congressional testimony reported in July, Hegseth went on to say that the Pentagon may experience “critical shortfalls” if it is not funded. The warning was about the department’s capacity to operate, replenish equipment and munitions, and meet other defense needs.

The inspector general’s findings provide an official accounting of how much ammunition was consumed and where the defense industry faces constraints in replacing it.

Iran War Exposed Gaps In Stockpiles

The central issue is not whether the United States has weapons available. The report establishes that the military continues to have substantial capabilities but that the Iran campaign reduced some inventories to levels the Pentagon considers strategic shortfalls.

The inspector general said expanding production requires significant lead time, while shortages of key components and skilled labor can further slow deliveries.

The Pentagon’s $33.4 billion estimate also remains a snapshot rather than a final cost of the conflict. It covers the operation through June 30, while infrastructure repairs and other costs may add to the eventual bill.

The report puts a government oversight finding behind months of debate over weapons consumption, industrial capacity and the cost of sustaining a prolonged military campaign.

The Pentagon faces the task of restoring affected inventories while ensuring the defense industry can expand production quickly enough to meet future operational demands.