The six-month-old U.S. war against Iran has cost roughly $38 billion, and the tab is projected to rise by about $3 billion a month, according to a Congressional Budget Office analysis released Tuesday — which found the conflict's most lasting cost may be a stockpile of missile-defense interceptors the Pentagon cannot quickly rebuild.

CBO tallied the expenses through Aug. 1. It estimates combat operations have consumed between one-half and two-thirds of the U.S. inventory of certain missile-defense interceptors since June 2025, leaving the military with fewer weapons available for a future conflict. Rebuilding those stocks could take at least five years, the agency found, even if production rates increase.

The estimate covers Patriot, Terminal High Altitude Area Defense, Standard Missile-3 and Standard Missile-6 interceptors. Because the Pentagon does not disclose how many it holds in inventory, CBO compared reported expenditures with the total number of missiles the Defense Department has purchased. The unit prices are steep: about $4 million apiece for a Patriot or SM-6, $12 million for a THAAD interceptor and $28 million for an SM-3. The weapons are also produced at relatively low rates. CBO said the United States had already spent significant quantities of them defending Israel before expending more during Operation Epic Fury.

Munitions dominate the bill. Of the $21.7 billion CBO estimates the Pentagon would need to replace what was expended through Aug. 1, interceptors account for $13.1 billion, land-attack cruise missiles another $7.3 billion and other munitions $1.2 billion. Beyond the missiles, the agency counted $10.4 billion for increased flying hours, $2.7 billion for fuel and $1.9 billion to replace equipment lost in battle — including a THAAD radar destroyed by Iran.

The figure is close to the $37.5 billion Defense Secretary Pete Hegseth reported at a Senate hearing on July 21. A separate Defense Department inspector general report put the cost of the operation at $33.4 billion through June 29. CBO noted that the Pentagon did not respond to its requests for information, so analysts relied on government databases and public reports. White House spokeswoman Anna Kelly called the strikes "decisive action" and said the military has "more than enough munitions, ammo, and stockpiles" to meet the commander-in-chief's goals; the Pentagon did not respond to a request for comment.

The wider economy is absorbing the shock. CBO expects the war to push inflation about half a percentage point higher in the first three months of 2027, with strained munitions stockpiles and higher energy prices raising concerns about Washington's ability to answer other potential conflicts. Reuters reported in August that the United States had used "virtually all" of its long-range precision missiles. Eighteen U.S. service members have died in the conflict, and the administration is searching for a way to end it and reopen the Strait of Hormuz.

The opening phase, Operation Epic Fury, committed about 250 tactical aircraft — roughly 90 of them from two carrier strike groups — plus an amphibious ready group, supported by bombers, airlifters, refueling tankers and Army air-defense units. Against that, the arithmetic is stark: the spending is measured in months, but the interceptor shortfall it leaves behind is measured in years, and the weapons burned through were the expensive, slow-to-build ones kept for exactly the next fight.

Sources: Defense News | The Business Times | CBS News | Greek City Times