The six-month U.S. war against Iran has cost $38 billion as of August 1, 2026, with monthly expenses projected to rise by $3 billion. According to a Congressional Budget Office report released on September 15, 2026, the conflict threatens to accelerate inflation, strain national munitions stockpiles, and drive up global energy prices.
The six-month-old military campaign in Iran has driven federal spending higher while creating profound strains on American defense capabilities, Congress’ nonpartisan bookkeeper reported on Tuesday, Sept. 15, 2026. The conflict has forced a rapid drawdown of military supplies and triggered economic repercussions that are expected to linger well into 2027.
Congressional Budget Office Figures and Rising Monthly Expenses
The Congressional Budget Office placed the direct cost of combat operations at $38 billion through August 1. Lawmakers learned that maintaining current operational tempos will add between $2 billion and $3 billion each month, depending on the intensity of the fighting. The new accounting tracked close to the $37.5 billion estimate that Defense Secretary Pete Hegseth reported to the Senate during a July 21 hearing.
The financial ledger compiled by Congress reveals that replacement expenses for expended weaponry make up the largest portion of the total. According to the CBO assessment, the Defense Department faces a $21.7 billion bill just to replenish exhausted ordnance, a figure that includes $13.1 billion for missile interceptors, $7.3 billion for land-attack cruise missiles, and $1.2 billion for miscellaneous munitions.
Munitions Depletion and Long-Term Defense Readiness
Beyond the immediate fiscal impact, the war has severely taxed the military’s inventory of precision-guided weapons. External reporting indicated that the U.S. had consumed virtually all of its long-range precision missiles. The CBO noted that rebuilding these stockpiles will likely take at least five years, even with active efforts to accelerate manufacturing.
This inventory deficit creates strategic vulnerabilities. The budget office warned that a reduced supply of interceptors could complicate the Pentagon’s response should a major conflict arise with an adversary possessing large numbers of ballistic and cruise missiles, such as China. During the July Senate proceedings, Hegseth pleaded for nearly $90 billion in emergency funding, warning senators that without these funds, we face critical shortfalls.
Base Destruction, Energy Shocks, and Economic Pressures
Physical damage to military installations has compounded the financial toll. A separate report from the Pentagon’s inspector general revealed that Iranian strikes damaged or destroyed hundreds of buildings on U.S. bases in the Middle East, alongside aircraft including fighter jets, refueling planes, and drones. That inspector general review fixed the cost of the war through June 19 at $33.4 billion, a figure that encompassed roughly $184 million in damage to diplomatic facilities.
Energy markets have absorbed immediate shocks from the conflict, particularly due to attacks in the Strait of Hormuz. Before hostilities began, roughly 20% of the world’s oil transited the narrow waterway. Disruptions there and at neighboring Gulf energy facilities pushed consumer and producer prices upward. The CBO projects that these cumulative economic pressures will increase inflation by 0.5% during the first three months of 2027.
Political Division and Administration Response
The cost inquiry was initiated at the request of Representative Brendan Boyle of Pennsylvania, the top Democrat on the House Budget Committee. Boyle issued a sharp critique of the administration’s strategy, pointing to both the financial and human costs of the conflict.
“Donald Trump’s disastrous war in Iran has already taken the lives of brave American servicemembers and left others wounded. Beyond that human toll, this nonpartisan CBO report makes clear that the war has also cost American taxpayers tens of billions of dollars and counting, while continuing to drive up costs.”
Rep. Brendan Boyle, top Democrat on the House Budget Committee
Administration officials defended the military actions as necessary to protect national interests. White House spokeswoman Anna Kelly characterized the campaign as decisive action
intended to prevent Tehran from harming U.S. personnel. Kelly asserted in a public statement that the military maintains more than enough munitions, ammo, and stockpiles to serve all of the Commander-in-Chief’s strategic goals and beyond.
Chief Pentagon spokesperson Sean Parnell likewise disputed the CBO’s findings regarding equipment shortages, maintaining that we have everything required to strike at the time and place of the president’s choosing.