It's funny as hell, actually.
I've seen a bunch of stuff like this article and the comments, and I'm seeing the Left recycling back to 2001 when war in Afghanistan was a terrible imperialist idea. When Iraq was invaded, suddenly Afghanistan became the "Good War," and there was a great lament that all this effort was going into Iraq when it should have gone to Afghanistan.
Now with Iraq down the liberal memory hole, it's all about Afghanistan again. America must be defeated.
Note in the comments the usual "king vampire" theory on bin Laden, that if only we had just gotten him way back then, all radical Islamists everywhere would have vanished in a puff of dust.