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U.S. President Donald Trump’s ongoing war against Iran is increasingly expensive and unpopular. It is also unauthorized and illegal, experts say. Why, then, is Congress seemingly unable to stop him?

The answer is more complicated than one might immediately imagine. It’s not just about a majority of votes in the House or Senate, because the president still has veto power. Lawmakers might have the power of the purse, but even if they somehow mobilized to block funding, it wouldn’t have an immediate impact. And then there are the courts, which lack a clear case to intervene in part because of the precedent that they have already set. The reality is that decades of political polarization, executive overreach, court rulings, and the general acquiescence of lawmakers have collectively brought the United States to a moment where Congress can start wars but do little to end them.

U.S. President Donald Trump’s ongoing war against Iran is increasingly expensive and unpopular. It is also unauthorized and illegal, experts say. Why, then, is Congress seemingly unable to stop him?

The answer is more complicated than one might immediately imagine. It’s not just about a majority of votes in the House or Senate, because the president still has veto power. Lawmakers might have the power of the purse, but even if they somehow mobilized to block funding, it wouldn’t have an immediate impact. And then there are the courts, which lack a clear case to intervene in part because of the precedent that they have already set. The reality is that decades of political polarization, executive overreach, court rulings, and the general acquiescence of lawmakers have collectively brought the United States to a moment where Congress can start wars but do little to end them.

“It’s a tragic commentary on the dysfunction of our political system that a war that is this unpopular can go on and on, and there is no practical way to stop it,” said Michael Glennon, a professor of constitutional and international law at Tufts University. The end result, Glennon added, is exactly the situation that the country’s Founding Fathers had hoped to avoid.

Any good story about a political and legal quagmire should probably begin with an arcane debate over definitions. Is the United States actually at war?

The 1973 War Powers Resolution requires a president to cease unauthorized military operations if they go without congressional authorization beyond 60 days, a threshold that the United States crossed on May 1. The Trump administration has claimed that the president is not bound by that requirement because a cease-fire on April 8 froze the clock and hostilities against Iran “have terminated.”

“That argument is factually and legally untenable,” said Glennon, who served as legal counsel on war powers issues for the Senate Foreign Relations Committee in the 1970s. “Legally, the text of the War Powers Resolution provides no basis for concluding that it’s possible to pause the clock, so I think the argument is frankly close to being frivolous.”

Congress never defined hostilities in the War Powers measure, but according to a December 2025 Congressional Research Service analysis, an official House report accompanying the 1973 law said the term should be understood to mean not just “a situation in which fighting actually has begun” but also “a state of confrontation........

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