It didn’t take long for the new House speaker, Mike Johnson, to demonstrate to the world that he will not be a serious partner for American allies or for those who still believe that governing is not a petty little game.

On Monday, only five days after being elevated to one of the most important leadership roles in the country, he upended a major foreign aid package for Ukraine, Israel and Taiwan, meekly obeying those Republican House members who see their main role as disengaging from the world and taking self-destructive potshots at Democrats. Nothing in Mr. Johnson’s record suggested he might try to shore up America’s leadership in the world, but his actions show that his new position has not added any gravitas to his thinking; he’s just pandering to his cronies in the far right wing.

Specifically, he stripped money for Ukraine and Taiwan from the $105 billion package requested by President Biden, leaving only the $14.3 billion the administration wants to send to Israel. But then he imposed a condition on the Israel money: Mr. Biden must agree to cut the same amount out of the money the Internal Revenue Service uses to chase down high-income tax cheats. So essentially the U.S. can protect Israel as long as it also protects rich white-collar criminals.

The I.R.S., of course, has nothing to do with the war between Israel and Hamas, but it has everything to do with the Republican desire to score political points whenever possible. Ever since Mr. Biden won $80 billion for stronger I.R.S. enforcement in the 2022 Inflation Reduction Act, Republicans have made that money a target, exploiting the agency’s Sheriff-of-Nottingham public image by trying to delude ordinary taxpayers into believing the extra funds meant the agency was coming after them.

But the aim of the extra enforcement was always the wealthy, whose complex tax fraud schemes cost the Treasury billions every year. Reducing the I.R.S. budget would actually widen the deficit, the opposite of what Republicans claim they care about. The Congressional Budget Office recently estimated that if the I.R.S. enforcement budget is cut by $25 billion, as some Senate Republicans have proposed, it would cost $49 billion in revenue from auditing the rich, and widen the 10-year deficit by nearly $24 billion.

Another study published earlier this year by the National Bureau of Economic Research found that every additional dollar spent on auditing high-income taxpayers yielded $12 in new revenue for the Treasury. By that calculation, Mr. Johnson’s stunt could cost the country $171.6 billion. Earlier this year, Republicans forced Mr. Biden to cut $20 billion from the I.R.S. as part of the price for avoiding a debt default; having shown that the White House would agree to chip away at a top priority to prevent a crisis, they are returning to the same playbook.

But in the end, the I.R.S. cut isn’t really going to happen, as House Republicans know, because Mr. Johnson’s bill will die in the Senate, where many leading Republicans already oppose it. Senator Mitch McConnell, the minority leader, has made it clear the final bill will have to include money for Ukraine, and hawks like Lindsey Graham of South Carolina have said the Ukraine money was related to Israel’s war against Hamas.

“Hamas was just hosted by the Russians in Moscow,” Mr. Graham said, adding, about Ukraine, “I think breaking them out sends the wrong signal.”

Other Republicans like Senator Mitt Romney of Utah and Representative Joe Wilson of South Carolina agreed with the White House that cutting the I.R.S. budget made little sense in the context of national security.

But making sense isn’t really Mr. Johnson’s game. He’s got a few calculations going on that show the kind of cynical strategic planning that current passes for politics in the House. By throwing in the I.R.S. cut, he gets to show the same extremists who deposed his predecessor that he can play rough with the White House. The move will presumably get some House Democrats to vote against the bill, and then Republicans can run misleading attack ads saying those Democrats oppose aid to Israel, as many members are already anticipating.

“The new Republican speaker has chosen to put a poison pill” in the aid bill, Representative Ritchie Torres, Democrat of New York, told Axios. “The politicizing of Israel in a time of war is nothing short of disgraceful.”

And then, assuming the bill does pass the House, Mr. Johnson will then get a seat at the table to negotiate with the Senate and the White House on the final legislation. If the House can’t pass anything, it will have less leverage in determining the final amount of aid.

If Mr. Johnson has substantive objections to helping Ukraine and Israel that justify the legislative impediments he is constructing, he should state what they are. There is room for a debate over conditions that could be imposed on military aid for Israel, including a detailed plan to protect civilians in the Gaza campaign, or, as my colleague Thomas Friedman has suggested, an agreement not to construct one new settlement in the West Bank outside existing settlement blocs and to rebuild the Palestinian Authority and the two-state solution at the expense of Hamas.

But that would require a serious discussion with serious people. And Mr. Johnson has now shown that he has no place in that room.