WASHINGTON: The war with Iran cost the US military around US$38 billion as of Aug 1, the nonpartisan Congressional Budget Office said Tuesday (Sep 15), with billions more potentially added to the price tag each month the conflict wears on.

“As of Aug 1, 2026, the armed conflict with Iran has cost (the Department of Defence) approximately US$38 billion,” said the CBO in a report, referring to the war that started after US-Israeli strikes targeting Iran from late February.

It added that depending on the intensity of violence, costs per month could range between US$2-$3 billion or more if the conflict continued.

The overall figures reflect the cost of replacing expended munitions and equipment lost in battle and increased fuel costs for the military, among other factors, the report said.

The price of replacing munitions used through Aug 1 was estimated at US$21.7 billion, with CBO noting that such replacements have been the largest single component of costs incurred by the Defence Department in the conflict.

The “main opportunity cost” for the department meanwhile has been the depletion of missile defence interceptors, leaving the United States with reduced inventory for several years.

Comparing the reported expenditures of missile defence interceptors with total numbers the department has bought suggests the United States “has probably used between one-half and two-thirds of its inventory of those munitions since June 2025”, the CBO warned.

The analysis was prepared following a request by Brendan Boyle, the top Democrat on the House Budget Committee, along with other Democratic lawmakers.