There is nothing wrong, or necessarily partisan to talk about the cost of war. You can't fight any war without there being a price paid. The question always boils down to gain versus costs. Like many, I understood and support Afghanistan more than Iraq because it made a little more sense as OBL was actually there, and Pakistan was and is a concern (what happens in Afghanistan matters to Pakistan).
This does not mean I agree with everything Obama has done. Both some of the mindless bombing and the surge of troops in Afghanistan seem more counter productive to me than more clearly defining our role and limits in that region.