Congressional Budget Office confirms cost of war with Iran reaches $38 billion

The U.S. Congressional Budget Office (CBO) confirmed on the 15th that the six-month-long war against Iran has cost US$38 billion (approximately NT$1,207.5 billion), and is expected to increase by US$3 billion (approximately NT$95 billion) per month in the future. The estimates come as the Trump administration seeks to end the conflict and reopen the vital Strait of Hormuz.

Reuters reported that the U.S. Congressional Budget Office pointed out in a report that as of August 1, U.S.-Iraq war expenditures had reached $38 billion. CBO also predicts that the war will increase inflation by 0.5 percentage points in the first three months of 2027.

The report said that rising war costs have put pressure on U.S. ammunition inventories and pushed up energy prices, raising concerns about the United States' ability to respond to other potential conflicts and tightening the federal budget.

This war cost estimate is quite close to the $37.5 billion announced by U.S. Secretary of War Pete Hegseth at a Senate hearing on July 21.

CBO said that most of the costs come from the rapid depletion of ammunition stocks, and estimated that it may take the United States five years to restock. Reuters reported in August that the United States had used "almost all" long-range precision missiles during the war.

CBO added in the report that the U.S. War Department did not cooperate with congressional financial auditors.

White House spokesperson Anna Kelly described U.S. President Trump's attack on Iran as "decisive action" to prevent Tehran from harming U.S. personnel or interests.

Kelly said in a statement that the U.S. military has "more than sufficient ammunition, arms and inventories to achieve all of the Commander-in-Chief's strategic objectives, and even more."

Pentagon spokesman Sean Parnell disputed the report's conclusion about ammunition shortages, saying: "We have all the resources we need to strike when and where the president chooses."

This war cost survey was conducted at the request of Pennsylvania Representative Brendan Boyle, a Democratic member of the U.S. House of Representatives Budget Committee.

"Trump's disastrous war in Iran has claimed the lives of heroic American service members and injured others," he said in a statement.

Boyle emphasized: "In addition to these human costs, this nonpartisan CBO report clearly shows that this war has also cost American taxpayers tens of billions of dollars, and the amount continues to increase, and it continues to drive up the costs."

So far, 18 US military personnel have been killed in the war with Iran.

Reuters pointed out that the CBO report did not include the costs incurred by the recent attacks on merchant ships in the Strait of Hormuz and attacks on US military facilities in the region. The report also did not include the borrowing costs derived from financing the war, which may increase the total cost of the war by tens of billions of dollars.