The financial burden of the United States’ military campaign against Iran has climbed beyond the Pentagon’s own projections, triggering fresh scrutiny in Congress after officials admitted the war has already cost nearly USD 29 billion.
The revised figure, disclosed during hearings on President Donald Trump’s proposed defence budget, comes barely weeks after the Pentagon estimated the conflict would cost around USD 25 billion. Even that number, experts argue, may only reflect a fraction of the actual economic fallout that could unfold over the coming years.
According to Pentagon Comptroller Jay Hurst, the updated estimate includes mounting operational expenses, repair costs and replacement of military equipment damaged or exhausted during the conflict.
“So, at the time of testimony from [the House Armed Services Committee], it was USD 25 billion, but the joint staff team and the comptroller team are constantly looking at that estimate, and so now we think it’s closer to 29,” Hurst told lawmakers during a House Appropriations Committee hearing.
“That’s because of updated repair and replacement of equipment costs and also just general operational costs to keep people in theatre,” he added.
However, the Pentagon acknowledged that the estimate still excludes damage sustained by US military bases across the region.
“We just don’t have a good estimate at this time,” Hurst later told a Senate Appropriations Subcommittee hearing.
Congress presses Pentagon over Iran war costs and military damage
The hearings quickly turned tense as senators repeatedly pressed Defence Secretary Pete Hegseth and Joint Chiefs Chairman General Dan Caine over the actual extent of damage inflicted on Iran and the long-term cost of the war.
Pentagon leaders declined to publicly disclose detailed battlefield assessments, arguing that the information could not be discussed in an open setting.
Democratic Senator Christopher Murphy cited reports suggesting Iran may still retain nearly 70 per cent of its missile and drone capabilities despite weeks of US strikes.
“With deep respect for the question, I’m not going to comment in this forum on what may or may not have been opined on by the IC,” Caine said, referring to the intelligence community.
Murphy questioned how Congress could continue approving war funding without transparent military assessments.
“How do we assess whether we should continue funding this if you can’t state to us what the assessments are?” he asked.
Hegseth also refused to publicly discuss battlefield evaluations.
“This is not a classified setting. We don’t talk about those things,” the defence secretary said.
At another point during the hearing, Hegseth criticised lawmakers for referring to leaked intelligence reports.
“Why would I validate what people may leak or not leak?” he asked.
Senator Brian Schatz also questioned whether the Pentagon had underestimated Iran’s retaliatory capabilities, particularly its drone operations and asymmetric naval tactics in the Strait of Hormuz.
“There are some data points that seem to indicate that we did not see all of this coming,” Schatz said, referring to emergency troop deployments, redeployment of missile defence systems and reported damage to US facilities in the region.
Hegseth rejected suggestions that the administration had been caught off guard.
“I can reassure you that it was all accounted for,” he said.
Experts warn Iran conflict could eventually cost USD 1 trillion
While Pentagon officials defended their estimates, outside experts warned the actual financial burden could be dramatically higher once long-term costs are included.
A recent Harvard Kennedy School research paper by war budgeting expert Linda Bilmes estimated that the total cost of the Iran conflict could eventually reach USD 1 trillion.
Bilmes said short-term operational expenses alone are nearing USD 2 billion per day.
“We are spending down munitions at an extraordinarily fast pace,” she said, noting that the US reportedly fired more Patriot missiles in the first four days of the Iran conflict than it had supplied to Ukraine over the past four years.
According to the research, the opening phase of the war alone cost the US at least USD 16 billion due to heavy use of advanced missile systems, combat deployments and operational spending.
Bilmes argued that Pentagon inventory valuations significantly understate actual replacement costs.
“For example, the Tomahawk missiles being used are valued at around USD 2 million each in inventory, but replacing them today costs USD 3 to USD 3.5 million,” she said.
“Patriot missiles in the inventory were valued at USD 1 to USD 2 million, but newer versions cost USD 4 to USD 5 million each.”
She also pointed to future spending tied to veterans’ healthcare, military expansion and defence manufacturing contracts involving companies such as Lockheed Martin and Boeing.
“I am certain we will spend one trillion dollars for the Iran war. Perhaps we have already racked up that amount,” Bilmes stated.
The expert also warned that the growing conflict could worsen America’s debt burden, which currently stands at around USD 31 trillion.