Why did President Obama decide to send 30,000 troops to Afghanistan? More specifically, as Washington Post policy blogger Ezra Klein is wondering, where did that 30,000 number come from? "Why not 50,000? Or 10,000? Or a draft?"

Klein acknowledges there may be perfectly "good answers to these questions," but he'd like to hear them--hopefully from the president himself:

Obama has been clear that this is far more important than Iraq. So why are we sending fewer troops than we sent to Iraq, even though Afghanistan is physically larger, with more difficult terrain, a weaker central government, and more strategic importance? ... Is it the foreign policy incarnation of the stimulus, wherein we need 60,000 and can't pass that through Congress?