The six-month US war against Iran has cost US$38 billion so far and could add another US$3 billion a month, according to the Congressional Budget Office (CBO), as the conflict continues to put pressure on government finances, inflation and military stockpiles.
The CBO said the war could raise US inflation by 0.5% in the first three months of 2027, with its assessment covering costs incurred through Aug 1.
A large share of the spending has come from the rapid drawdown of munitions, which the CBO estimated could take up to five years to replenish. The shortage could also affect the Pentagon’s ability to respond to another major conflict, including a potential confrontation involving China and Taiwan.
The mounting costs come as attacks around the Strait of Hormuz have pushed up energy prices. The waterway carried about 20% of global oil supplies before the war, making disruptions a concern for consumers and producers.
The CBO’s estimate is close to the US$37.5 billion cost reported by Defence Secretary Pete Hegseth at a Senate hearing in July. Hegseth had also sought nearly US$90 billion in emergency funding to replenish munitions.
The Pentagon disputed the CBO’s assessment of munitions shortages.
“We have everything required to strike at the time and place of the president’s choosing,” said Chief Pentagon spokesperson Sean Parnell.
White House spokeswoman Anna Kelly described President Donald Trump’s attacks on Iran as “decisive action” to prevent Tehran from harming US personnel or interests, saying the US military had “more than enough munitions, ammo, and stockpiles to serve all of the Commander-in-Chief’s strategic goals and beyond.”
The CBO said its accounting did not include the costs of recent attacks on commercial vessels in the Strait of Hormuz or strikes on US military installations in the region. It also excluded borrowing costs associated with financing the war, which could add tens of billions of dollars.
The Pentagon’s inspector general separately estimated that the war had cost US$33.4 billion through June 19, including around US$184 million in damage to US diplomatic facilities from Iranian strikes.
Eighteen US military service members have died in the conflict, according to the report.
The rising war bill comes as US public debt surpassed US$40 trillion in August, adding to pressure on the federal budget.
Reuters
