Congressional Watchdog Puts War Costs at $38 Billion, Estimates 5 Years to Replace Interceptors

The Congressional Budget Office (CBO) reported that the U.S. war in Iran has cost approximately $38 billion as of August 1st, after five months of fighting. This figure covers expenses such as replacing expended munitions and equipment lost in battle, increased flying hours, other operational costs, and higher fuel expenditures. The CBO also projects that continued operations will cost the Department of Defense an additional $2 billion to $3 billion per month, depending on the intensity of the conflict.

A significant portion of these costs, $21.7 billion, is attributed to replacing munitions, with $13.1 billion specifically for interceptors, $7.3 billion for land-attack cruise missiles, and $1.2 billion for other munitions. The report highlights that the conflict has consumed between one-half and two-thirds of the U.S. inventory of certain missile-defense interceptors since June 2025. Rebuilding these stocks, which include Patriot, THAAD, Standard Missile-3, and Standard Missile-6 interceptors, is estimated to take at least five years, even with increased production rates.

Beyond munitions, other substantial costs include $10.4 billion for increased flying hours, $2.7 billion for fuel, and $1.9 billion to replace equipment lost in battle, such as a THAAD radar destroyed by Iran. The CBO's estimate, while subject to uncertainty due to the Pentagon's lack of direct response to data requests, utilized government databases and public reports. A separate Pentagon inspector general report estimated the cost through June 29th at $33.4 billion, including $22.3 billion for munitions alone.

This substantial expenditure of resources and the depletion of critical missile defense systems, particularly during initial defensive actions against Iranian ballistic missile and drone attacks, pose a significant challenge for U.S. military readiness. The report notes the high unit costs of these interceptors, ranging from approximately $4 million for a Patriot or SM-6 to $28 million for an SM-3, emphasizing the financial and logistical burden of replenishing these vital assets.