The US Senate rejected a plan on July 30, 2026, that would have forced President Trump to pull US forces out of the conflict with Iran unless Congress specifically voted to authorize the fighting. The vote was 49 to 50 (The Guardian).

Under the US Constitution, Congress has the power to declare war, while the president serves as commander in chief of the military. In practice, presidents have often sent troops into combat without a formal declaration of war, and lawmakers have sometimes pushed back using something called a "war powers resolution" — a vote that forces the president to end military action that Congress never approved.

This was the second time in two weeks the Senate tried to pass such a measure (The Guardian). On July 23, 2026, the Senate voted 49 to 47 against advancing a similar resolution, blocking it (Reuters). That vote came within hours of the House of Representatives approving its own version to curb Trump's Iran war powers (Reuters). The Senate held Roll Call Vote 207 on July 23, 2026, on a joint resolution to direct the removal of United States Armed Forces from hostilities (Senate.gov).

On July 30, Senator John Fetterman, a Democrat from Pennsylvania, was the only member of his party to vote against the resolution. Three Republicans — Susan Collins of Maine, Lisa Murkowski of Alaska, and Rand Paul of Kentucky — voted in favor (The Guardian). Senator Mitch McConnell was absent, still recovering from a fall in June and not yet cleared by doctors to return to work (The Guardian).

Lawmakers have tried several approaches this year to limit the president's authority over the Iran conflict. Senators Tim Kaine, Chuck Schumer, and Adam Schiff introduced a bipartisan resolution on January 29 (Kaine Senate Press). On June 23, 2026, the Senate voted 50-48 in favor of a resolution to halt the Iran war, pushing back against Trump (Reuters). The House had already passed a similar measure earlier that month (Reuters).

The latest push came after a ceasefire — a formal pause in fighting, usually meant to allow for negotiations — between the United States and Iran fell apart on or before July 13, 2026. Senator Schiff filed a new war powers resolution that same day (Schiff Senate Press). The text of S.J.Res.114 states that President Trump ordered air strikes inside Iran's territory on February 28, 2026 (Congress.gov). The Congressional Research Service, a nonpartisan research arm of Congress, published a report titled "War Powers Issues: U.S. Use of Military Force Against Iran" on June 23, 2025 (Congress.gov).

In the House, lawmakers have introduced multiple resolutions in the current Congress (2025-2026). H.Con.Res.38 directs the President to stop using US Armed Forces against Iran or any part of its government (Congress.gov). H.Con.Res.86 uses a specific section of the War Powers Resolution to order the removal of US forces from hostilities with Iran (Congress.gov).

The Guardian article does not specify the resolution number or the sponsor of the war powers measure voted on July 30, 2026 (The Guardian).

The broader context here is a long-running tug-of-war over who gets to decide whether the United States goes to war. The June 23 Senate vote, which passed 50-48, showed a brief moment of bipartisan agreement to push back against the president. But the July 23 failure and the July 30 vote of 49-50 show that the group of lawmakers supporting Congress's war powers authority has not stayed together. Senator McConnell's absence removed a vote that could have changed the result or narrowed the gap, since he has generally defended the Senate's role in war decisions. Senator Fetterman's vote against the resolution shows how complicated Iran policy is for Democrats, with some members torn between progressive anti-war views and broader national security concerns. The ceasefire collapse in July gave new urgency to these efforts, but the results so far point to a shrinking path for those who want to limit the president. The repeated votes suggest that members of Congress see this constitutional question as unresolved and important, even though their efforts to constrain the president keep falling short. With each round, the outcome shifts based on who shows up and which party has defectors, but the July 30 result means the president can keep conducting hostilities against Iran without a specific congressional authorization.