What happened
The Congressional Budget Office has estimated that the ongoing war with Iran could cost the United States approximately $2 billion to $3 billion per month. The office reported that the conflict has already directly cost the US around $38 billion between February 28 and August 1. This figure does not include the cost of repairing damaged US bases in the region.
The majority of the costs incurred during the war are attributed to replacing munitions, particularly interceptor missiles used to defend against incoming missiles. The CBO noted that the large expenditure of these missiles has left the US with a reduced inventory, which could become problematic if a conflict were to arise with an opponent possessing a large arsenal of ballistic and cruise missiles, such as China.
The report also estimated that the US has likely used between one-half and two-thirds of its inventory of certain munitions since June 2025. The CBO analysis estimated that it will cost around $21.7 billion to replace the munitions used in the conflict, with an additional $1.9 billion needed to replace lost equipment.
The White House and the Pentagon have downplayed concerns about depleted weapons inventories, with President Trump stating that the US has a surplus of ammunition. However, the CBO said the Defense Department did not respond to requests for information.
The estimated monthly cost of the war could rise if the conflict escalates, with the CBO noting that the war in July cost around $3 billion. The report was released in response to a request from Democratic Rep. Brendan Boyle, who criticized the war's cost to American taxpayers and its human toll.
