CBO puts the Iran war at $38 billion through August 1 and $2 to $3 billion a month after that

The Congressional Budget Office said Tuesday that U.S. combat operations against Iran cost about $38 billion through August 1 and will run $2 billion to $3 billion each month if the fighting stays at recent levels. The 19-page analysis is the most complete public tally of the war's price since it began in late February alongside Israel.

CBO said the Pentagon did not answer its requests for information. The office built the estimate from government databases and public reporting. The figure is close to the $37.5 billion Defense Secretary Pete Hegseth gave a Senate hearing on July 21. A Pentagon inspector general report issued hours earlier had put costs through the end of June at $33.4 billion. Two more months at $3 billion each sit near CBO's total.

Munitions dominate the bill. CBO put replacement costs at $21.7 billion: $13.1 billion for missile-defense interceptors, $7.3 billion for land-attack cruise missiles and $1.2 billion for other rounds. Increased flying hours account for nearly $11 billion. Equipment lost in battle is about $1.9 billion. Extra fuel is about $3 billion, some of it from higher prices after Iran closed the Strait of Hormuz. The office did not price damage to American bases in the region.

The stockpile warning is the part that will last after the monthly burn rate fades from headlines. CBO said the United States has probably used between one-half and two-thirds of certain interceptor inventories since it joined Israeli strikes on Iranian nuclear sites and began shooting down the reply. Rebuilding those magazines "could take at least five years." Reuters reported in August that the country had used "virtually all" of its long-range precision missiles in the campaign.

Monthly costs depend on intensity. At the level of violence seen in May and June, CBO said another month would cost about $2 billion. At July's level it would cost about $3 billion. "Monthly costs would be higher if the conflict intensified further or DoD used expensive munitions," the report added. The office also said the war would raise inflation by 0.5 percent in the first three months of 2027.

Those numbers arrive less than two months before midterm elections and while the administration is looking for a way to end the fighting and reopen Hormuz. They do not include veterans' care, interest on borrowed money, or the wider economic cost of a closed strait. They also do not include Iranian or Israeli spending. They are a Defense Department operating bill as reconstructed by Congress's scorekeeper.

The composition of the $38 billion tells commanders what they have spent down. Interceptors protect ships and bases. Cruise missiles hit targets ashore. Flying hours keep carriers and tankers in the air. When those three lines are the bulk of a war bill, the country is burning the tools it would need for a second crisis. Five years to refill some of those tools is a constraint on any later plan in the Pacific or Europe.

CBO was careful about what it could not see. Base-repair costs are missing because the department would not share them. Classified munitions may be undercounted. Fuel prices move with the strait. The $2 billion to $3 billion monthly range is a function of those gaps as much as of tactics. Still, three independent tallies now sit within a few billion dollars of each other: Hegseth in July, the inspector general through June, and CBO through August 1.

Lawmakers who have to pass a funding bill this autumn now have a number they can argue over. The war has already consumed more than half of the administration's total war-spending request, CBO noted. Every additional month at July's pace adds another $3 billion and takes another bite from magazines that factories cannot refill on a political timetable. That is the concrete takeaway from Tuesday's letter. The cost is no longer an argument. It is a table.