Update: On Thurs­day, the Sen­ate passed Sens. Sanders and Lee’s bipar­ti­san res­o­lu­tion 56 – 41 direct­ing Pres­i­dent Trump to end U.S. mil­i­tary sup­port for the Sau­di-led war in Yemen — the first time Con­gress has ever debat­ed leg­is­la­tion invok­ing the War Pow­ers Act.

The resolution provides Congress its proper authority to answer the question of whether the United States should provide resources to a cruel and destructive war in the Middle East.

After more than three and a half years of par­tic­i­pa­tion in the ruth­less Sau­di-led war on Yemen, the Sen­ate on Wednes­day took the most sig­nif­i­cant step yet towards stop­ping Amer­i­can involve­ment in the onslaught, which has killed tens of thou­sands of people.

The Sen­ate vot­ed 63 – 37 in favor of hold­ing a debate on Sen­ate Joint Res­o­lu­tion 54–intro­duced by Sens.Bernie Sanders (I‑Vt.), Mike Lee (R‑Utah) and Chris Mur­phy (D‑Conn.). The mea­sure invokes the War Pow­ers Res­o­lu­tion of 1973 to force a vote to ​“remove Unit­ed States Armed Forces from hos­til­i­ties in or affect­ing the Repub­lic of Yemen.” This is the first time a cham­ber of Con­gress has advanced a War Pow­ers Res­o­lu­tion, and it marks a con­sid­er­able vic­to­ry for oppo­nents of the war, whose pre­vi­ous efforts to debate the res­o­lu­tion nar­row­ly failed in the Sen­ate in March after 10 Democ­rats came out in opposition.

The devel­op­ment came after oppo­nents of the war staged protests tar­get­ing the offices of key Sen­a­tors. ​“With mil­lions of Yeme­nis on the brink of star­va­tion, those of us who’ve long cam­paigned for Con­gress to end the US war on Yemen are anx­ious­ly await­ing the vote on S.J.Res.54, which is now final­ly pos­si­ble,” said Shireen Al Adei­mi, an assis­tant pro­fes­sor at Michi­gan State Uni­ver­si­ty and activist who mobi­lized in sup­port of this resolution.

The mea­sure requires the Unit­ed States to end its par­tic­i­pa­tion in the war ​“unless and until a dec­la­ra­tion of war or spe­cif­ic autho­riza­tion for such use of Unit­ed States Armed Forces has been enact­ed.” To date, Con­gress has not held a vote on U.S. par­tic­i­pa­tion in the Sau­di-led war.

Ahead of the vote on the Sen­ate floor Wednes­day, Sen. Sanders said, ​“The fact is the Unit­ed States, with almost no media atten­tion, has been Sau­di Arabia’s part­ner in this hor­rif­ic war. We have been pro­vid­ing bombs the Sau­di-led coali­tion is using, refu­el­ing their planes before they drop those bombs, and assist­ing with intel­li­gence. And in too many cas­es our weapons are being used to kill civilians.”

While the vote does not, in itself, end the Sau­di-led war, it is the lat­est indi­ca­tion that polit­i­cal winds are shift­ing against it. The war has pushed Yemen to the brink of the worst famine in a cen­tu­ry – leav­ing 30 per­cent of the country’s chil­dren under the age of five suf­fer­ing from acute mal­nu­tri­tion, or ​“wast­ing,” accord­ing to the Under-Sec­re­tary-Gen­er­al for Human­i­tar­i­an Affairs at the Unit­ed Nations. As a result of the war, over 3 mil­lion Yeme­nis have been inter­nal­ly dis­placed, the coun­try con­tin­ues to suf­fer the worst cholera out­break in mod­ern his­to­ry and more than 8 mil­lion chil­dren lack access to safe water and san­i­ta­tion. The sit­u­a­tion in Yemen is wide­ly seen as the worst human­i­tar­i­an cri­sis in the world, and the U.S.-Saudi coali­tion is respon­si­ble for the vast major­i­ty of civil­ian deaths.

The res­o­lu­tion, how­ev­er, includes a carve-out that per­mits ​“oper­a­tions direct­ed at al Qae­da or asso­ci­at­ed forces.” This excep­tion essen­tial­ly green­lights the U.S. government’s ongo­ing—and dead­ly — covert drone war, and deploy­ment of a clas­si­fied num­ber of troops, pur­port­ed­ly to fight Al Qae­da. Notably, the Sau­di-led war has allowed Al Qae­da to gain sig­nif­i­cant ter­ri­to­ry — and there is evi­dence the U.S. coali­tion has fought along­side Al Qae­da affiliates.

The vote fol­lows a spate of high-pro­file atroc­i­ties, includ­ing the Sau­di-led coalition’s August 9 bomb­ing of a school bus in Yemen’s north­ern Saa­da province that killed 54 peo­ple, 44 of them chil­dren. As momen­tum turns against the war, even for­mer Oba­ma admin­is­tra­tion offi­cials such as Saman­tha Pow­er and Ben Rhodes are com­ing out against the war, albeit play­ing down the Oba­ma administration’s respon­si­bil­i­ty for unleash­ing and over­see­ing U.S. par­tic­i­pa­tion in the onslaught.

On Novem­ber 9, Pres­i­dent Trump claimed that he would sus­pend the U.S. military’s mid-air refu­el­ing to assist airstrikes in Yemen. How­ev­er, this deci­sion can be reversed, and it has been insuf­fi­cient to pres­sure the Sau­di coali­tion to stop the bomb­ings. As recent­ly as Novem­ber 26, a moth­er and her five chil­dren were killed in a Sau­di-led airstrike.

Trump lat­er affirmed the U.S. alliance with Sau­di Ara­bia on Novem­ber 20 and cleared that country’s lead­er­ship of wrong­do­ing in the killing of Wash­ing­ton Post colum­nist Jamal Khashog­gi. Khashoggi’s mur­der, wide­ly seen as a tar­get­ed polit­i­cal assas­si­na­tion ordered by Sau­di Crown Prince Mohammed bin Salman, sparked inter­na­tion­al out­rage and led many polit­i­cal lead­ers to call for a more aggres­sive response from the U.S. government.

And on Novem­ber 27, CNN report­ed that ​“The U.S. has ​‘slammed the brakes on’ a Unit­ed Nations Secu­ri­ty Coun­cil res­o­lu­tion call­ing for a lim­it­ed cease­fire and increased human­i­tar­i­an aid in Yemen over con­cerns about anger­ing Sau­di Ara­bia,” accord­ing to two sources.

With the Trump admin­is­tra­tion unwill­ing to take any steps to end U.S. par­tic­i­pa­tion in the Sau­di-led war on Yemen, the res­o­lu­tion pro­vides Con­gress its prop­er author­i­ty to answer the ques­tion of whether the Unit­ed States should pro­vide resources to a cru­el and destruc­tive war in the Mid­dle East.

Two of the Demo­c­ra­t­ic hold­outs on sup­port­ing the res­o­lu­tion were Rhode Island Sens. Jack Reed and Shel­don White­house. David Segal, exec­u­tive direc­tor of Demand Progress and for­mer Rhode Island state rep­re­sen­ta­tive, was part of a large-scale effort to push the sen­a­tors to get behind the leg­is­la­tion. ​“Reed and White­house have received hun­dreds of calls from con­stituents over the last few days, and much more pres­sure spread through­out the year.”

After Sen. Reed announced he would sup­port the res­o­lu­tion on Tues­day night, the punk band Down­town Boys had hun­dreds of fans join a call to Sen. White­house to demand he too back the leg­is­la­tion. On Wednes­day, White­house also backed the measure.

The res­o­lu­tion will now move the Sen­ate floor for debate. If it pass­es, it will next move to the House of Rep­re­sen­ta­tives for a vote, either in the lame duck ses­sion or in the new Con­gress which will fea­ture a larg­er pro­por­tion of Democ­rats. If the res­o­lu­tion pass­es both bod­ies it would then move to Pres­i­dent Trump’s desk where he could either sign or veto it. How­ev­er, veto­ing a bill to empow­er Con­gress, a co-equal branch of gov­ern­ment, to have a say in U.S. for­eign pol­i­cy and invoke its Arti­cle 1 pow­ers under the Con­sti­tu­tion would like­ly spark a major back­lash from both cham­bers. As Sen. Sanders said on Wednes­day, ​“Con­gress has not autho­rized the war in Yemen and there­fore the war is unconstitutional.”

“Three years ago, the notion of Con­gress vot­ing to cut off mil­i­tary sup­port for Sau­di Ara­bia would have been polit­i­cal­ly laugh­able,” said Paul Kawi­ka Mar­tin, senior direc­tor for pol­i­cy and polit­i­cal affairs at Peace Action. ​“This suc­cess­ful vote in the Sen­ate is a tes­ta­ment to the col­lec­tive pow­er of a coali­tion of peace groups, human rights groups, and grass­roots activists across the coun­try mak­ing calls, orga­niz­ing ral­lies, and meet­ing with mem­bers of Con­gress to make the case for end­ing the U.S. role in the war in Yemen.”