The United States Congress is set to vote this week on measures aimed at limiting President Donald Trump’s authority as he prosecutes a war against Iran, though the Republican majority is expected to back him.
Since returning to the White House in 2025, Trump has moved to significantly broaden executive powers, drawing concerns from lawmakers who argue that only Congress has the constitutional authority to declare war.
Senator Tim Kaine sharply criticised the military action, writing on X that “Trump has launched an unnecessary, idiotic, and illegal war against Iran,” shortly after the United States and Israel began operations overnight Friday into Saturday.
Back in January, amid a major US troop buildup in the Middle East, Kaine introduced legislation seeking to compel Trump to secure congressional approval before entering any military conflict with Iran. On Saturday, he called on lawmakers to reconvene immediately to debate his resolution, with a vote anticipated this week.
US Secretary of State Marco Rubio and Defense Secretary Pete Hegseth briefed lawmakers at the Capitol on Monday regarding the unfolding conflict.
Following the meeting, Senator Mark Warner, the top Democrat on the Senate Intelligence Committee, told reporters, “There was no imminent threat to the United States of America by the Iranians. There was a threat to Israel.”
He warned that equating a threat to Israel with a direct threat to the United States would place the country in “uncharted territory.”
Is the war legal?
The question of whether Iran posed an imminent threat lies at the center of the legal debate. While Congress alone can formally declare war, the 1973 War Powers Act permits the president to initiate limited military action in response to an emergency caused by an attack on the United States.
At a Monday press briefing, Hegseth referred to the confrontation as a “war,” rather than a restricted intervention. Trump, in a late-night address announcing the start of major combat operations, maintained that Iran represented an “imminent” danger to the United States.
According to Daniel Shapiro of the Atlantic Council, the president did not clearly outline the urgency or immediate threat that justified launching the conflict at this time. He noted that presidents typically present their objectives to the public and provide comprehensive briefings to Congress—steps he said were not taken in this case.
Sixty-day clock
The White House disclosed that it formally notified eight senior congressional leaders shortly before hostilities began. Under the War Powers Act, Trump must seek congressional authorization if military operations extend beyond 60 days.
Republican Representative Thomas Massie, a frequent critic of Trump within his party, denounced the action and announced plans to introduce a bipartisan bill with Democratic Representative Ro Khanna to compel a congressional vote on the conflict.
“The Constitution requires a vote, and your Representative needs to be on record as opposing or supporting this war,” Massie wrote on X.
However, most Republicans are expected to oppose the proposed measures. Even if passed, any such legislation would likely face a presidential veto, which would require a two-thirds majority in both chambers to override.
