A combination of early presidential maneuvering and internal policy debate is feeding yet another iteration of that media perennial: the great Republican crackup. This time it's tea-party insurgents versus get-along establishment fogies fighting principally over two things: national security and Obamacare.

National security

New Jersey Gov. Chris Christie recently challenged Sen. Rand Paul over his opposition to the National Security Agency metadata program. Paul has also tangled with Arizona Sen. John McCain and other internationalists over drone warfare, democracy promotion and, more generally, intervention abroad.

So what else is new? The return of the most venerable strain of conservative foreign policy - isolationism - was predictable. GOP isolationists dominated until Pearl Harbor and then acquiesced to an activist internationalism during the Cold War because of a detestation of communism.

With communism gone, the conservative coalition should have fractured long ago. This was delayed by 9/11 and the rise of radical Islam. But now, 12 years into that era, the natural tension between isolationist and internationalist tendencies has resurfaced.

Both parties are internally split on domestic surveillance, as reflected in the close House vote on curbing the NSA. This is not civil war. It's a healthy debate.

The more fundamental GOP divide is over foreign aid and other manifestations of our role as the world's leading power. The Paulites, pining for the splendid isolation of the 19th century, want to leave the world alone on the assumption that it will then leave us alone.

Which rests on the further assumption that international stability - free commerce, relative tranquillity - comes naturally. If only that were true. Unfortunately, stability comes about only by Great Power exertion. World order is maintained by American power and will. Take that away and you get chaos.

That's the Christie-McCain position. They figure that America doesn't need two parties of retreat. Paul's views are still in the minority among conservatives but gathering strength. Which is why Christie's stroke - defending and thus seizing the party's more traditional internationalist consensus - was a signal moment in the run-up to the 2016 campaign. The battle lines are drawn.


The other battle is about defunding Obamacare. Led by Sens. Mike Lee and Ted Cruz, the GOP insurgents are threatening to shut down the government on Oct. 1 if the stopgap funding bill contains money for Obamacare.

This is nuts. Obama will never sign a bill defunding the singular achievement of his presidency. Especially when he has control of the Senate. Especially when, though 51 percent of Americans disapprove of Obamacare, only 36 percent favor repeal. President Obama so knows he'll win any shutdown showdown that he's practically goading the GOP into trying.

Never make a threat on which you are not prepared to deliver. Every fiscal showdown has rebounded against the Republicans. The first, in 1995, effectively marked the end of the Gingrich revolution. The latest, last December, led to a last-minute Republican cave that humiliated the GOP and did nothing to stop the tax hike it so strongly opposed.

Those who fancy themselves tea-party patriots fighting a sold-out cocktail-swilling establishment are demanding yet another cliff dive as a show of principle.

But there's no principle at stake here. This is about tactics. If I thought this would work, I would support it. But I don't fancy suicide. It has a tendency to be fatal.

How many times must we learn the lesson? You can't govern from one house of Congress. You need to win back the Senate and then the presidency. Shutting down the government is the worst way to get there. Indeed, it's Obama's fondest hope for a Democratic revival.

Charles Krauthammer's email address is letters@charleskrauthammer.com