Senate Tells Trump: End the Iran Military Campaign or Ask Congress First

On June 23, 2026, the Senate voted to tell President Trump he must either stop U.S. military operations in Iran or come back to Congress to ask for permission to continue them. The New York Times reported on the vote, which concluded a five-month push by Democrats that eventually passed both the House and Senate.

The vote was not automatic. Senators Tim Kaine (D-VA), Chuck Schumer (D-NY), and Adam Schiff (D-CA) first called for a vote in late February. In March, they and others introduced new versions of the measure and pushed the Senate leadership to hold hearings. In May, Republican Senator Bill Cassidy of Louisiana broke with his party to help move the vote forward, clearing a procedural hurdle. The House had already passed its version on June 3 by a vote of 215 to 208, per official records.

To understand what this vote means, you need to know about a law from 1973. That year, Congress passed the War Powers Resolution, which says a president cannot keep troops in a military conflict for more than 60 days without asking Congress first. Congress needs to either give the president permission to continue (called an "authorization for use of military force" or AUMF) or formally declare war. The idea was to prevent presidents from waging wars on their own without the legislative branch having a say.

When Congress passes a resolution like the Senate just did, it is technically supposed to force the president to pull out troops. But here is the catch: presidents have always argued that Congress actually cannot enforce this. It is a gray area in the law, which is why the same fight has played out with administrations since the 1970s.

Senator Elissa Slotkin of Michigan, who sits on the Senate Armed Services Committee and used to work at the Defense Intelligence Agency, voted for the resolution, calling the Iran operation a "war of choice." Her background gave her words real weight in this debate.

So what does this actually change? Even though no president has ever felt legally bound by one of these resolutions, passing one sends a message. It is like Congress putting a marker down: "We do not agree with how this war is being conducted." If Trump wants to keep fighting in Iran, he now has to go back to Congress and ask for official permission. That is much harder than starting a war quietly and hoping Congress stays quiet.

Cassidy's vote is worth noting. Republicans usually stick with their president on military matters. His decision to break ranks suggests either that some Republicans have doubts about this campaign or that he felt strongly about Congress's constitutional power.

Trump's administration has not said yet whether it will obey the resolution, ask Congress for permission, or claim the resolution is not legal. What the administration does next will set the terms for this fight between the White House and Congress.