With the Senate set to vote Thursday afternoon on a resolution that could end U.S. support for the Saudi-led bombing campaign in Yemen, hawkish Republican Sen. Tom Cotton, R-Ark., introduced two last-minute amendments that would have largely undermined it.

The Senate approved the anti-war measure 56 to 41 without Cotton’s amendments, setting the stage for the House of Representatives to take up the measure after January. If it passes in the new Congress, it would direct President Trump to remove U.S. forces from hostilities stemming from Saudi Arabia’s intervention in Yemen, which has killed thousands and contributed to the world’s worst famine.

The measure was introduced by Sens. Bernie Sanders, I-Vt.; Chris Murphy, D-Conn.; and Mike Lee, R-Utah, and failed 55-44 in March. But following the killing of Washington Post contributor Jamal Khashoggi by Saudi agents in Turkey, it gained broader support.

Cotton’s first proposed amendment, which was defeated by a voice vote, would have allowed the U.S. to give Saudi Arabia “materials and advice” as long as they were “intended to reduce civilian casualties or further enable adherence to the Law of Armed Conflict.” That would essentially have meant business as usual, because the Obama and Trump administrations have consistently claimed since the fighting began in 2015 that their backing — which includes providing weapons, intelligence, and logistical support — was aimed at reducing civilian casualties.

In a letter to the Senate earlier this year, Defense Secretary James Mattis wrote, “Since 2015, the United States has provided limited support to Saudi-led coalition military operations … focused on improving coalition processes and procedures, especially regarding compliance with the law of armed conflict and best practices for reducing the risk of civilian casualties.”’

Cotton’s second amendment would have created an exception when U.S. assistance is intended to “disrupt Houthi attacks against locations outside of Yemen.” In retaliation for the bombing campaign, the Houthis, a Yemeni rebel group that is fighting the Saudis, have conducted ballistic missile attacks on targets inside of Saudi Arabia.

The Saudis frequently cite such attacks as a justification for their intervention. For instance, after the coalition bombed a school bus full of children in August, the Saudi Press Agency quoted coalition spokesperson Turki al-Malki saying the attack was a “legal military action to target elements that planned and executed the targeting of civilians.”

“Sen. Cotton’s amendments are a cynical attempt to leverage civilian protection concerns — not toward conflict de-escalation, but in favor of continuing U.S. support in perpetuity,” said Eric Eikenberry, advocacy officer for the Yemen Peace Project. “Senators voting for these amendments are knee-capping the very message they claim to want to send to the coalition regarding the thousands of Yemeni lives lost.”

In response to congressional pressure, the Trump administration has already decided to cut off its mid-air refueling support for coalition warplanes. But the move did not stop opponents of the war in Congress from demanding the complete withdrawal of U.S. support.

Update: December 13, 2018 4:18 p.m. EST

This story has been updated to reflect the outcome of the Senate vote on the measure and proposed amendments.