As the U.S.-Iran war’s price tag grows by the day, funding the conflict threatens political peril for Republicans who control Congress.
When lawmakers return from recess next week, the GOP faces a high-stakes fight to approve new war funding amid objections from both within the party and from Democrats. Key details remain unsettled — including the total cost so far and how much the White House will request next. The White House has not provided detailed breakdowns; the Center for Strategic and International Studies (CSIS) estimates the cost to date at nearly $30 billion.
Republicans also face a ticking clock under the 1973 War Powers Resolution, which terminates military operations after 60 days without congressional approval (the president can invoke a 30-day extension). That deadline has sharpened concerns from a growing number of GOP lawmakers who have publicly questioned aspects of the war and the administration’s transparency.
Sen. Susan Collins, R-Maine, criticized President Trump’s “incendiary” rhetoric and called for a “swift” end to the conflict, saying she would not vote to send ground troops or to extend hostilities past 60 days “unless there is a dramatic change.” “If the president commits boots on the ground, sends ground troops to Iran, I believe that congressional authorization for such action is completely required under the War Powers Act,” Collins said, adding that congressional approval is also necessary if hostilities last beyond 60 days.
Other Republicans have voiced similar positions. Sen. John Curtis, R-Utah, wrote that he will not support ongoing military action beyond a 60-day window without congressional approval, citing historical and constitutional reasons. Senators Thom Tillis, Todd Young and Lisa Murkowski, along with Reps. Don Bacon and Mike Lawler, have also warned of the need for congressional engagement if the conflict drags on. Young urged Congress to reengage its oversight role and evaluate any requests for additional resources or authorities. Murkowski said the administration must be more transparent and provide public briefings rather than letting lawmakers learn developments through media reports.
A costly war
When it comes time to approve money, Republicans will consider multiple paths: a supplemental funding bill, or using the reconciliation process to try to bypass Democratic opposition. Last week the White House sought roughly $1.5 trillion for defense in fiscal 2027, but it’s unclear how much of that is tied specifically to Iran.
Mark Cancian, a senior advisor at CSIS who has worked on cost estimates, said there has been discussion of a supplemental in the $80 billion to $100 billion range to cover the war. Cancian identifies costly weapon systems and damage to U.S. aircraft and infrastructure as major drivers of the estimated $29 billion cost so far. The Washington Post reported the U.S. has fired more than 850 Tomahawk cruise missiles in the conflict — more than in any other U.S. war — at about $3.6 million apiece. Cancian said the U.S. may have lost roughly $1 billion in military jets and other aircraft, and the dramatic rescue of two airmen in Iran, which involved the loss of several aircraft, may have cost about $500 million.
With razor-thin Republican majorities in both chambers, GOP leaders cannot afford many defections. Some conservatives have objected to the war outright and plan to oppose funding. Sen. Rand Paul and Rep. Thomas Massie, both fiscal conservatives from Kentucky, have been among those opposing expanded war powers and funding; Paul has co-sponsored Democratic measures to limit presidential war powers in Iran, Venezuela and other conflicts.
Where Democrats stand
Democrats are working to thwart the GOP funding push and to repeatedly put Republicans on the record about the war in an election year. House Democrats recently tried and failed to force a vote to limit Trump’s war powers in Iran; next week both House and Senate Democrats are expected to press additional war-powers votes. “No president, Democrat or Republican, should take this country to war alone. Not now, not ever,” Senate Minority Leader Chuck Schumer said, urging Republicans to join Democrats in ending what he called a “reckless war of choice.”
Democrats are also tying criticism of the war to affordability issues expected to dominate the campaign trail. “Gas prices are skyrocketing, the cost of living is out of control and billions of taxpayer dollars are being wasted dropping bombs in Iran, while Republicans refuse to spend a dime to make life more affordable for everyday Americans,” House Minority Leader Hakeem Jeffries said.
Beyond direct federal expenditures, analysts say households will face indirect costs through higher fuel, grocery and travel prices. Roger Pielke Jr., a senior fellow at the American Enterprise Institute, estimated that the spike in gasoline and diesel prices through April 1 could cost Americans roughly $12.1 billion — about $92 per household — with jet fuel increases adding about $2.2 billion through higher airfares. U.S. farmers could face an extra $131 million in fertilizer costs that will be passed on to consumers.
“There has been some discussion and debate over the cost of the war to the federal government. Taxpayers pay that and that’s real money,” Pielke said. “But it turns out that the costs go well beyond that and filter through the economy due to the effects of the war, most visibly on the Strait of Hormuz.”
Democrats themselves are not uniformly united. Last month Sen. John Fetterman and Reps. Henry Cuellar, Juan Vargas and Jared Golden voted against limiting Trump’s Iran war powers. However, as the conflict continues and Congress returns, some of those positions could shift.
Mark Cancian noted that Democrats’ complaints about transparency, authorization and costs will intensify, but added that if the president can keep Republicans unified, Democrats may have limited ability to block funding.