It is strange yet increasingly likely that the first veto our isolationist president issues will be aimed at extending U.S. intervention in a foreign conflict that has no direct bearing on American national security interests.

Even stranger, critical opposition to that intervention in a Republican-led Senate is what’ll ultimately force that veto.

Not a done deal yet, though. For the moment, only the Democratic-led House has weighed in. But it did so with 18 Republicans in the majority.

“We can go after Iran another time and heaven knows I’ve been the sponsor of many resolutions and bills sanctioning Iran,” House Foreign Affairs Committee chairman Rep. Eliot Engel (D-N.Y.) said. “There is a civil war going on now in Yemen and innocent children are dying. We have an ability to put an end to that and that’s what we should do with this humanitarian crisis, it’s critical that we don’t delay.”…

Even if Trump ultimately vetoes the resolution, sponsors argued, the resolve of both the Senate and the House will send a message to the parties equipped to end the conflict.

“Each of these milestones, this has had a dramatic consequence on the actual negotiations in Yemen,” [Dem Rep. Ro] Khanna said, referring to the Senate’s passage of a similar resolution last year. “I do think the famine will be averted if the war powers resolution passes the House and Senate.”

That’s a fine thought, that unhappiness in Congress might force the Saudis to the bargaining table with the Houthis and Iran, but there’s little Congress can do without veto-proof majorities so long as Trump is all-in on the Saudi alliances. As for the Senate, it might surprise you to learn that this stands a real chance of passing McConnell’s chamber. It shouldn’t, though. The GOP has been much more likely to break with Trump on foreign policy than on domestic goals, having passed new sanctions on Russia in 2017 and more recently a resolution splitting with him on withdrawals from Syria and Afghanistan.

They’ve already rebuked him on Yemen too, in fact. It might have gotten lost in the post-midterm holiday news slowdown this past December but a resolution backed by Bernie Sanders and Mike Lee calling for an end to U.S. assistance to the Saudis in Yemen passed 56-41. That bill expired when the previous Congress ended and the new one began, but if they had 56 votes before they should have at least 51 two months later. (Of the seven Republicans who voted yes on December’s resolution, only Jeff Flake has left the Senate.) McConnell can’t prevent a floor vote on the new House bill either, in case you’re thinking that he might have that ace up his sleeve. Assuming today’s bill proceeds to the Senate and passes, we’re headed for Trump’s very first veto.

His only hope is that Senate Republicans get cold feet now that their votes mean something. In December it was clear that the Republican House wouldn’t bring any Yemen resolutions to the floor, leaving GOPers in the upper chamber free to vote their consciences without fear that the Yemen bill might land on Trump’s desk and force a showdown with POTUS. The calculation is different now.

Some Republicans, mindful of an embarrassing veto showdown with Mr. Trump, are looking for other ways to show their dissatisfaction…

Mr. Menendez and Senator Todd Young, Republican of Indiana, introduced legislation last week that would impose broader sanctions on the Saudi government, including a ban on American refueling of Saudi coalition aircraft in Yemen, without calling for a removal of military support.

That might be Trump’s and McConnell’s only play. They can’t stop the vote and they probably can’t command enough loyalty from the caucus to deny Schumer the four GOP votes he needs unless they offer people like Susan Collins some cover in the form of an alternate resolution. Give them a way to express their disdain for the Saudis post-Khashoggi that doesn’t involve trying to curb Trump’s power to help the Saudi war in Yemen and maybe they’ll take that in the name of avoiding a confrontation with the White House. But don’t be too sure. The Senate is annoyed right now with Trump because he refuses to comply with the deadline for a report on who’s responsible for Jamal Khashoggi’s murder. Some strong-form hawks like Marco Rubio won’t dare punish him for that by trying to revoke his authority in Yemen, but less committed Republican interventionists might. It seems likely that this bill is going to pass and Trump’s going to veto it to protect the Saudi war machine. And then it’ll go back to Congress where the two-thirds veto-override attempt will fail badly.

Which is a bummer even if you support U.S. assistance to Saudi Arabia. If the Senate passes the House bill, it’ll be the first time since the War Powers Act was passed under Nixon that Congress has tried to limit the president’s authority over an undeclared war. We are way, way overdue for a legal battle between the legislature and the executive over how much constitutional power the president enjoys to wage war (or assist in waging war, in this case) without the green light from the people’s representatives. Maybe Trump would be able to sidestep that legal battle by arguing that what the U.S. is doing in Yemen doesn’t quite rise to the level of hostilities within the definition of the War Powers Act but it’d be nice to at least have that argument in front of a judge. If you want more legislative power over warmaking, this is as low-stakes a test case as one can imagine. Too bad Congress (still) doesn’t have the political will to force the issue.