By Caitlin Yilek
March 4, 2026 / 6:00 AM EST / CBS News
Washington — The Senate is scheduled to hold a vote Wednesday on a resolution that would bar President Trump from committing U.S. forces to further military operations against Iran without congressional authorization, after the administration launched a major campaign over the weekend and provided changing explanations of its objectives.
Sen. Tim Kaine, D-Va., forced the vote with a war powers measure co-sponsored by Republican Sen. Rand Paul of Kentucky. The resolution would “direct the removal of United States Armed Forces from hostilities within or against the Islamic Republic of Iran that have not been authorized by Congress.” Kaine pushed a similar measure in June, after U.S. strikes on sites tied to Iran’s nuclear program, but that effort failed.
With Republicans holding a 53-seat majority, the resolution is expected to fall short of the votes needed to move forward. Sen. John Fetterman, D-Pa., has said he will oppose the measure, which means it would need backing from at least four Republicans in addition to Paul to succeed. In June, most Democrats and Paul supported the Iran measure while Fetterman sided with Republicans.
Even if Congress approved the resolution, it would likely be largely symbolic: the president could veto it, and overturning a veto would require two-thirds majorities in both the House and Senate. Kaine acknowledged long odds but said it was important to force senators to state their positions on authorizing force. “If you don’t have the guts to vote yes or no on a war vote, how dare you send our sons and daughters into war where they risk their lives,” he said.
Mr. Trump said Monday the operation in Iran was expected to last four to five weeks, while adding the United States has the “capability to go far longer than that.” He said the campaign was “substantially ahead of our time projections” and did not rule out the possibility of deploying ground troops.
Democrats who attended a classified briefing with administration officials on Tuesday said they were unsatisfied and warned the action could produce more U.S. casualties. “They told us in there that this is an open-ended operation that hasn’t even really started in earnest yet,” Sen. Chris Murphy, D-Conn., said. “There will be more Americans killed. They refuse to take off the table, the insertion of ground troops.” Sen. Cory Booker, D-N.J., said there was “clearly … no imminent threat.”
A CBS News poll found a majority of Americans disapprove of the war with Iran and believe the administration has not clearly explained its objectives; roughly half of respondents think the conflict could stretch on for months or years.
Senate Majority Leader John Thune, R-S.D., defended the administration, saying its actions were “consistent with what previous administrations have done” and that “the president was perfectly within his rights to take the steps that he took.” Secretary of State Marco Rubio told reporters that while no presidential administration has fully accepted the War Powers Resolution as constitutional, this administration “complied with the law 100%, and we’re going to continue to comply with it.”
The Constitution grants Congress the authority to declare war. The 1973 War Powers Resolution requires the president to consult Congress “in every possible instance” before introducing U.S. forces into hostilities, to report to Congress within 48 hours when forces are deployed without a declaration of war, and limits unauthorized engagements to 60 days unless Congress provides authorization.
In a notification to Congress Monday, Mr. Trump cited “repeated efforts to achieve a diplomatic solution to Iran’s malign behavior,” saying the threat to the United States and its allies “became untenable” and that “it is not possible at this time to know the full scope and duration of military operations that may be necessary.”
Kaine said he may continue to force votes in coming weeks and suggested some senators who initially oppose the resolution could change their minds as the situation develops. He noted Republicans at one point supported a war powers measure related to Venezuela earlier this year before the effort faltered under administration pressure.
Sen. Josh Hawley, R-Mo., who has previously backed limits on presidential use of force in other contexts, said he believes the administration is complying with the law on Iran and plans to vote against Kaine’s resolution. Hawley reiterated that authorizing ground troops would require congressional approval.
The Senate vote comes ahead of a similar measure expected to be considered in the House later this week.
Ibrahim Aksoy, Patrick Maguire and Grace Kazarian contributed to this report.
In: United States Senate; Iran; Donald Trump