We have a timetable.

President Obama is sending 30,000 additional troops to Afghanistan but plans to conclude the war and withdraw most U.S. service members within three years, senior administration officials told CNN Tuesday.

The president is ordering military officials to get the reinforcements to Afghanistan within six months, White House officials said…

Obama, whom Republicans had accused of “dithering” over the decision, came to the conclusion that the deployment needs to be accelerated to knock back the Taliban, the officials said.

The push for a speedy deployment surprised some observers, because White House officials who defended Obama’s slow pace of coming to a decision had said the Pentagon wouldn’t be able to get new troops to Afghanistan that quickly.

Instead of the usual military protocol of “hurry up and wait,” The One’s been playing a game of “wait, then hurry up.” He promised you Change, didn’t he? As for the timetable, at first blush I thought it was an obvious political calculation to push the horizon safely beyond the next presidential election, in much the same way that ObamaCare wouldn’t kick in until 2013 or 2014. But that makes no sense. For one thing, it’ll be obvious by election time whether the escalation succeeded or failed and that’s what he’ll be judged on, not on how many soldiers are in the field. If things are going well, voters won’t begrudge him a broken promise to keep troops there longer than he’d planned. Especially since thousands of other troops are due home from Iraq in 2011.

For another thing, unless and until Petraeus or McChrystal says it’s time to go, you won’t reach any sort of critical mass among conservatives or right-leaning independents in opposition to the war. And without that critical mass, the GOP nominee’s not going to get up there at a debate and hammer The One aside from the ritual grumbling about not “fighting to win” or whatever. He has more to fear from his base for escalating than he does from Republicans, but his base is a paper tiger too. For all its bluster, does anyone seriously think MoveOn’s not going to go to bat for Obama in 2012 when the alternative is Mitt Romney or — gasp — Sarah Palin? Long story short, I can only assume The One favors a timetable because he thinks it’s a good idea on the merits, politics be damned. Although why he thinks that, given that (a) one of the Taliban’s biggest advantages among the population is its relative staying power, (b) the Afghan army is nowhere near ready to take over, and (c) we’re evidently about to toss some sort of international babysitter for Karzai into the mix, I have no idea.

Michael Crowley reminds us that Obama’s withdrawal timetable from Iraq was and presumably still is contingent upon the conditions on the ground (which famously brought him into alignment with McCain during the campaign), so perhaps there’ll be a loophole or two mentioned tonight. Something to watch for. Also worth watching for: The final number on troops, of course, which continues to bounce between 30,000 and 34,000 even with the speech hours away, and the requisite hand-wringing about cost, which would make this — at a fraction of the price of the stimulus, TARP, or ObamaCare — somehow the first federal initiative that’s too expensive for Obama and the Democrats.

Update: Ah, and here’s that loophole now. Crowley again:

In a conference call, the White House clarifies what those reports about a three year time line were about. Although the phrase three years doesn’t appear anywhere in Obama’s speech, he will set July 2011 as the date when NATO forces will begin handing over the lead of combat operations to Afghan forces…

And along those same lines, a senior White House official speaking on background says: “This is the beginning of a process which is not yet defined in terms of the length of the process, or the endpoint.” Sounds fairly open-ended to me–as it realistically has to be, given the uncertainties involved and Obama’s apparent belief in the necessity of winning.

“Handing over the lead” can mean a lot of things, just as “finishing the job” can. The Iraqi army’s been in the lead in their country for awhile now, in fact, and U.S. forces inside the country are still robust. On the other hand, this isn’t a three-year timeline, it’s a two-year timeline, which is awfully fast. Exit quotation from Crowley’s source: “If the Taliban thinks they can wait us out, then they are misjudging the president’s approach.”