Congratulations to 51-year-old Louisiana Rep. Mike Johnson, who with a 220-209 vote Wednesday won the unenviable job of herding the cats, snakes and peacocks in the GOP menagerie. Opinion: Potomac Watch WSJ Opinion Potomac Watch Mike Johnson is the GOP's New Speaker of the House Explore Audio Center The question is whether the Republican malcontents will let him govern in a way they refused his deposed predecessor, Kevin McCarthy. It won’t take long to find out. Government funding expires Nov. 17, and America’s friends in Israel, Ukraine and Taiwan need military help to defend themselves. Mr. Johnson was first elected in 2016, representing a district that voted for Donald Trump by double digits. The optimistic case is that he might have the credibility on the right to get the GOP’s narrow majority to accept the modest wins of divided government. Maybe it will take a Speaker like Mr. Johnson to convince the disruptive Republican rump that accepting partial victory is better than a government shutdown or an eventual spending omnibus. Mr. McCarthy did the GOP a favor by averting a shutdown that would have backfired on Republicans, but he needed Democratic votes to pass a 45-day spending bill. That was the excuse used to justify the revolt against him, though personal animus was the real driver. In a letter this week, Mr. Johnson proposed a roadmap for passing spending bills, with a potential stopgap extension through early next year to gain the time to do it. Good luck and Godspeed. A second priority is rebuilding military deterrence, including arms for Israel, Ukraine and Taiwan. Mr. Johnson was an early opponent of assistance to Kyiv. After voting against a $40 billion package last year, he offered a litany of red herrings, such as that “our own border is in chaos,” and “mothers are struggling to find baby formula.” Such problems have nothing to do with the U.S. interest in deterring Vladimir Putin’s Russian imperialism. Most of Mr. Johnson’s GOP colleagues see that, and his broader role as Speaker should take this into account, even if mounting evidence of a Russia-Iran axis hasn’t changed his mind. Another part of Mr. Johnson’s job will be below the surface, and that’s where his predecessor did some of his best work

More From The Wall Street Journal (subscription required):