In my previous post, I struggled with the compelling interests that would keep the US, Canada and NATO in Afghanistan. I didn't really get at a key aspect that was in the back of my mind yesterday: the so-called Pottery Barn rule of intervention--you break it, you bought it. I do think that the US and NATO have some responsibility to clean up the mess that they helped make over the past thirty years or so--arming extremists, leaving Afghanistan to rot in the aftermath of the Soviet pullout, the minimal effort made after the Taliban were knocked out, etc.
This is not quite the sunk cost argument (although it is somewhat close) that we spent x billions and y lives, so we need to stick around. Instead, the argument is that we have to be responsible about when and how we depart. If there is one lesson from Vietnam that folks on various ends of the political spectrum can agree, it is that the US left Southeast Asia irresponsibly, leaving our allies to their fates in South Vietnam and providing the opportunity for the Khmer Rouge to rise in Cambodia and so on. This is one of the reasons why I was opposed to the war in Iraq--that it would be very hard to exit and the US might be facilitating genocide if it left quickly. Even as the US tries to follow through on its agreement with the Iraqi government, it is becoming clear that the Iraqis may not have been ready for it.
This is moving from a realist/pragmatic argument about what is best for the US and NATO to a moral one about what we owe the Afghans, moving from where I am pretty comfortable to where I have no expertise--normative arguments. Knowing that I am pretty weak here, I will stick with the focus on costs and benefits of sticking around, but I had to acknowledge one of the key reasons to stick around--an obligation to leave things better off if we can. Of course, that is a big if and I will ponder that tomorrow.