On the verge of the upcoming G20 meeting in Argentina, President Donald Trump finds himself facing a new adversary in the realm of foreign policy — Congress.

In a 63-37 vote on Wednesday, 14 Republicans joined every Democratic senator to move forward on a resolution rescinding U.S. support for Saudi Arabia’s war in Yemen.

At last members of Trump’s own party have found the gumption to stand up for American values, even at the risk of the angering the president. We wish that Sens. John Cornyn and Ted Cruz were among them, however, and encourage the two Texas Republicans to change their minds before the resolution comes to a final vote.

The war in Yemen has become a nightmare, and this serves as an appropriate opportunity for Congress to start reasserting the power it has unwisely ceded to the White House after the Sept. 11 attacks.

Since 2015, the impoverished Arab nation has been embroiled in a bloody civil war. Saudi Arabia has spent the past three years leading a bombing campaign against Iran-aligned Houthi rebels that ousted a Saudi-friendly president.

The Obama administration supported the Saudi campaign by supplying precision-guided munitions and aerial refueling, while encouraging them to avoid civilian casualties. We also deployed Green Berets to assist Saudis and fired missiles at Houthi-controlled radar sites. The Trump administration has continued this support even as the Saudi campaign sinks into quagmire and the number of civilians deaths continue to climb.

Earlier this year a U.S.-made bomb struck a school bus and killed 40 children. At least 50,000 children are dead as a result of ongoing famine due to the war, and a cholera outbreak has likely infected more than 1 million people.

All of this inhumanity, for a military mission that the United States can no longer justify.

The United States originally got involved in this war to support regional allies. We agreed with Saudi Arabia’s conclusion that a coup next door in Yemen could threaten its government. But things have changed, not just in terms of the conduct of the war, which has turned ugly, but also in our relations with the Saudis.

The murder of Washington Post journalist Jamal Khashoggi in a Saudi consulate revealed just how little regard Saudi crown prince Mohammad bin Salman holds for U.S. values and residents. That killing has senators reconsidering our relationship with Saudi Arabia, and they’re coming to terms with the fact that the United States doesn’t seem to have a direct interest at stake in the Yemen War.

Secretary of State Mike Pompeo and Defense Secretary Jim Mattis tried to convince key senators otherwise, and made a rare classified briefing to senators ahead of the vote. Their argument apparently fell flat with a bipartisan majority of Senators.

“I found their briefing today to be lacking,” Senate Foreign Relations Committee Chairman Bob Corker, R-Tenn., said before the vote. “I found that in substance we’re not doing those things that we should be doing to appropriately balance our relationship with Saudi Arabia between our American interests and our American values.”

Closer to home, no Texan — including Cornyn and Cruz — should have much sympathy for the Middle East kingdom that purposely crashed oil markets in 2014 in a futile attempt to drive frackers out of business. Since then, the United States has eclipsed Saudi Arabia as the world’s largest oil producer. This shift in energy markets should have us rethinking our direct national interest in the medieval Islamic kingdom.

Since the beginning of the war on terror, Congress has neglected its constitutional power to make war and control the purse strings. Democrats and Republican alike have gladly yielded authority to an executive branch that has gone unchecked for far too long. The Authorization for Use of Military Force passed after the Sept. 11, 2001 terrorist attacks has been used to justify troop deployments and military actions in 20 different nations, many of which have little — if anything — to do with the al Qaeda terrorists responsible for the original atrocity.

Congress needs to tighten its reins on the Pentagon, and it can start with Yemen.