Technically, McChrystal had asked for 80,000 troops but that was apparently a “throwaway” number that he never expected to get and wasn’t even the option he himself recommended. What he recommended was 40,000. And he’s going to get something close to that. (McClatchy reported yesterday that the magic number is 34,000.) This is the prudent thing to do, both strategically and politically. Strategically, it’s simply too risky to follow Biden’s counterterror approach by ceding parts of the country to the Taliban and trusting them not to host AQ; if that bet turns out badly, you’re left with an even more dire situation internally and no public will whatsoever to send more troops to deal with it. Politically, an untested president can’t afford not to show some muscle in his first big wartime test, especially if he’s a liberal and especially if he spent the better part of, oh, 18 months explaining why Afghanistan is a must-win. If he pulled out completely, the GOP would destroy him for it. If he sent a token presence, not enough to win but enough to “lose with dignity,” he’d have to explain how that’s worth hundreds or thousands more casualties. And he wouldn’t be able to.

Long story short, it’s good news. But:

The first combat troops would not arrive until early next year and it would be the end of 2010 before they were all there. That makes this Afghanistan surge very different from the Iraq surge, in which 30,000 troops descended on Baghdad and the surrounding area in just five months.

Fred Kagan of the American Enterprise Institute says a slow motion surge will produce slow motion results.

“If they’re going to be sort of trickled in very slowly over the course of a year than it’s unlikely to have a very decisive impact in the course of 2010,” he said.

If it’s a question of freeing up enough troops to rotate them in more quickly, The One has plenty of political cover to accelerate withdrawal in Iraq thanks to the “thrilling breakthrough” in the Iraqi parliament to pass the country’s election law. I’m not saying that’s the right thing to do — on the contrary, if Obama’s going slow on pulling out there because he doesn’t want to destabilize the country so soon after those mega-attacks in Baghdad, then more power to him — but that might warrant a new review now too. I don’t know if he’d get majority support among conservatives for doing that, but if he sold it as part of his plan to get those troops to McChrystal, where they’re most needed, the opposition at least would be muted. Something to watch for.