US war against Iran has cost about $38 billion through August, CBO estimates

The Congressional Budget Office reported the US military campaign against Iran has cost approximately $38 billion through August 2026, with costs projected to rise roughly $3 billion monthly, driven mainly by the rapid drawdown of munitions stockpiles.

Why this matters. The rising, disclosed cost trajectory gives Congress a concrete budget figure to weigh against continued war funding requests and future munitions replenishment votes.