It could be that Boehmer and others are just claiming that we ought to give the President and his plan the benefit of the doubt. But, of course, his plans for this war haven't exactly been sterling.
So that leaves him to fall back on that other old nut of an argument, that if we were to withdraw we would be giving al-Qaeda exactly what they want. It seems that we already did this when we invaded--we removed a secular albeit evil ruler and opened the way for sectarian violence of exactly the sort that al-Qaeda desires in the region.
Is it in their interest that we leave? Or is it in their interest that we come more and more to look like a long-term occupier of Iraq? Should every decision we take always rely on a consideration of what the many dispersed leaders of al-Qaeda may think is in their interest? I don't know. What I do know is that, in spite of the Pottery Barn rule, sometimes things you break can't be fixed, or at least not very easily.