Overview
- The Congressional Budget Office released its assessment on Sept. 15 saying the Department of Defense spent roughly $38 billion through Aug. 1 and that the war could cost $2 billion to $3 billion more each month depending on fighting intensity.
- CBO estimates $21.7 billion is needed to replace weapons used so far, including about $13.1 billion for missile‑defense interceptors and $7.3 billion for land‑attack cruise missiles.
- The report finds the U.S. likely used between one‑half and two‑thirds of its interceptor inventory since June 2025 and warns rebuilding those stocks will take years because of supply bottlenecks in rocket motors, propellants and skilled labor.
- CBO projects the conflict will raise inflation, estimating about a 0.5 percentage‑point boost to headline inflation in Q1 2027 as energy and shipping disruptions through the Strait of Hormuz and the Red Sea push up fuel and transport costs.
- The estimate covers direct DoD outlays for munitions, lost equipment, fuel and extra operations but excludes many large items such as long‑term veterans’ care, repairs to damaged bases, diplomatic costs and borrowing costs, and it notes additional uncertainty because the Defense Department did not provide requested data.