He promised to do so on the campaign trail, and now he’s done it: President Barack Obama has approved a troop increase to Afghanistan. His just-released statement is below. Notice that the forces approved appears to be less than the 20,000-30,000 troops that Gen. David McKiernan, commander of U.S. and NATO troops in Afghanistan, has asked for. Also notice that Obama says that the troop increase does not "pre-determine" his ongoing strategy review.

There is no more solemn duty as President than the decision to deploy our armed forces into harm’s way. I do it today mindful that the situation in Afghanistan and Pakistan demands urgent attention and swift action. The Taliban is resurgent in Afghanistan, and al Qaeda supports the insurgency and threatens America from its safe-haven along the Pakistani border.

To meet urgent security needs, I approved a request from Secretary Gates to deploy a Marine Expeditionary Brigade later this spring and an Army Stryker Brigade and the enabling forces necessary to support them later this summer. This increase has been requested by General McKiernan and supported by Secretary Gates, the Joint Chiefs and the Commander of Central Command. General McKiernan’s request for these troops is months old, and the fact that we are going to responsibly drawdown our forces in Iraq allows us the flexibility to increase our presence in Afghanistan.

This reinforcement will contribute to the security of the Afghan people and to stability in Afghanistan. I recognize the extraordinary strain that this deployment places on our troops and military families. I honor their service, and will give them the support they need.

This increase is necessary to stabilize a deteriorating situation in Afghanistan, which has not received the strategic attention, direction and resources it urgently requires. That is why I ordered a review of our policy upon taking office, so we have a comprehensive strategy and the necessary resources to meet clear and achievable objectives in Afghanistan and the region. This troop increase does not pre-determine the outcome of that strategic review. Instead, it will further enable our team to put together a comprehensive strategy that will employ all elements of our national power to fulfill achievable goals in Afghanistan. As we develop our new strategic goals, we will do so in concert with our friends and allies as together we seek the resources necessary to succeed. [My emphasis.]

I suppose that means that this is a force increase to answer McKiernan’s request of what he needs now — though it doesn’t appear to be all of what McKiernan wants — rather the resources required for the forthcoming change in strategy. Interestingly, Secretary Gates told the Senate Armed Services Committee that he would oppose any increase in forces beyond what McKiernan has already asked for. If that holds, this is probably the only plus-up that’s on the way. Update: As commenter Macacquerman just pointed out below, Gates could conceivably ask for the remainder of McKiernan’s request at a later point. I wrote fast on this one and outpaced basic logic. But I read Gates’ comments at the SASC hearing as meaning that there wouldn’t be another round of troop requests after the Big Plus-Up Debate of 2009 — which, of course, he did not actually say. So: my fault on this one.

Update: Brandon Friedman from VoteVets approves.

One More Update: The Pentagon’s out with its own statement, and it clarifies the troop level picture. We’re talking 12,000 combat soldiers and marines, plus another 5,000 support troops, for a plus-up of 17,000 by the summer. 

Absolute Total Final Update, I Promise: Maybe that troop total should include the additional troops marked last year for deployment, which gets us pretty close to McKiernan’s range.

Crossposted to The Streak.