CBO says Iran war has cost more than $38 billion and sharply reduced U.S. missile stockpiles

The U.S. war with Iran has cost the Pentagon more than $38 billion through Aug. 1 and is expected to keep adding billions of dollars each month, according to a new Congressional Budget Office assessment. The report also says the conflict has sharply reduced U.S. stocks of key missile interceptors, underscoring the strain the war has placed on defense readiness.

The CBO said the fighting has affected not only spending but also the military’s ability to replace advanced munitions quickly. Among the weapons drawn down are Patriot, Terminal High Altitude Area Defense, Standard Missile-3 and Standard Missile-6 interceptors, all of which are central to U.S. air and missile defense. The report’s conclusions add to an expanding picture of the war’s toll on U.S. forces and equipment.

The latest estimate follows earlier reporting that the conflict has already imposed heavy costs on U.S. bases, aircraft and regional operations. Separate Pentagon oversight work estimated the cost of the campaign at $33.4 billion through June 29, showing that different federal assessments can vary depending on the date covered and what expenses are included.

Stockpile pressures and long-term costs

According to the CBO, the war cost about $38 billion between Feb. 28 and Aug. 1, with roughly $7.3 billion tied to land-attack cruise missiles, $13.1 billion to missile-defense interceptors and $1.2 billion to other munitions. The office said the operation could continue to cost as much as $3 billion a month, depending on how intense the conflict remains.

The assessment does not include some costs already absorbed in the federal budget, such as basic military operating expenses, and it also leaves out repairs to U.S. bases damaged during the conflict. That means the full financial impact may be larger than the headline estimate suggests.

The report also warns that the war has created strategic inventory shortfalls and exposed bottlenecks in the defense industrial base. Military contractors are expected to need years to replenish some advanced missile systems, a delay that could leave the U.S. with less flexibility if another major conflict develops before stockpiles recover.

For now, the report adds a new federal benchmark for the war’s cost and its effect on readiness. It also highlights a broader concern in Washington: that the expense of sustained military operations can extend well beyond the battlefield, shaping budgets, procurement and the pace at which the armed forces can rebuild depleted inventories.