So it's a valid question, and one that falls on the COIN advocates to answer: How much more money should we spend, how many more lives should we sacrifice, to support a regime that isn't bothering to build the loyalty of its own people—a regime whose ultimate interests appear to be much different from ours?
This isn't to say that the United States and NATO should abandon Afghanistan. Nor is it remotely to say that this is what Obama is doing. Senior administration officials emphasized earlier in the day that there will still be 68,000 U.S. troops by the end of next summer and that the counterterrorism campaign—the raids and airstrikes advocated by the CT-Plus advocates—will continue with no reduction or let-up.
Meanwhile, the programs to train the Afghan forces, as well as to provide them with logistics, intelligence, and other forms of support and assistance, will remain the same—could possibly even be boosted. (Obama has left it to his commanders to decide how to pace the drawdown and how to reconfigure the U.S. forces that remain.)
The strategy is thus stripped down to its basics: to keep al-Qaida out; and to keep "degrading" the Taliban and other insurgents so they are incapable of taking over the government of Afghanistan or huge swaths of its territory. The United States and several other countries have a security interest in these goals, independent of what Karzai wants. Any war goal more ambitious than those vital interests may at this point be beyond us—not least because, as has been clear for a long time now, Karzai is doing everything he can to undermine those goals.
This isn't to say that the critics of the accelerated drawdown are wrong. Obama's actions, and even more his announcement of the actions, will make it harder for U.S. and Afghan troops to stave off the Taliban militarily and to win over the Afghan people politically.
But it may also send a message to Karzai that he really does have to get serious about reform. And, it may send a message to Afghanistan's neighbors that they really do have to start playing an active role in helping to stabilize the country—or else risk the stability of their whole region. All along, officials from Obama, Gates, Clinton, and Petraeus on down have said that these kinds of wars tend to end not with a military victory but with a political settlement. If Obama couples his military drawdown with a surge in diplomacy pressure, this may all turn out for the best.