Pentagon Watchdog Says the Iran War Cost $33.4 Billion in Four Months and Drained Key Munitions Stocks

The United States Department of Defense inspector general told Congress that the campaign against Iran has produced shortfalls in the country's munitions inventory. The mandatory report covering 28 February to 30 June put the cost of the operation at 33.4 billion dollars, of which 22.3 billion dollars went toward munitions that were fired. The report found that the expenditure "has resulted in strategic inventory shortfalls and revealed industrial base bottlenecks for munitions resupply".

The specific constraints named are upstream manufacturing inputs rather than finished weapons: solid rocket motors, high-grade explosives and propellants, according to the report as described by France 24. These are the components with the longest lead times and the fewest qualified suppliers, which means additional funding cannot quickly produce delivered rounds.

Air-defense stocks saw the heaviest drawdown. By August the army had used close to 80 percent of its stockpile of Terminal High Altitude Area Defense (THAAD) interceptors and about half of its Patriot missiles, reporting on the watchdog's findings states. The report also lists aircraft losses, including four F-15s destroyed, one F-35 damaged, seven KC-135 tankers damaged and up to thirty MQ-9 Reaper drones destroyed.

An interceptor inventory depleted to that degree changes what the United States can credibly promise elsewhere. Air defense is the scarce resource in every current conflict, and stocks committed to the Gulf are not available to Ukraine, to Taiwan, or to allied deployments in Europe. That scarcity is a physical constraint on American commitments, independent of budget decisions in Washington.