Kevin Drum asks if the Iraq war proves preemptive war is a bad idea. Since the has been recent upheaval of who was right about the war, I thought I'd put up my own views.
While some of my opposition to the war was that I believed at that time the incompetence of the Bush administration as evidenced by decisions made at Tora Bora and the tossing aside of proven military doctrines to experiment, I'm not sure that's germane to the question of preventive war, and it's probably less important.
The greater prewar failure was the inability of the Bush administration to engage the international community and its almost perverse desire to go it alone. The American people are simply more predisposed to accepting such adventurism, which was sold as preemptive but was really preventive, than the rest of the world, especially at that time with 9/11 so fresh.
This forced us to act pretty much unilaterally. Remember the coalition of the willing. That joke of group was virtually bereft of international power, and more importantly, cash to pay for the fiasco. They were just a bunch of toadies willing to put their name on the list.
I just really don't think you can pull off an Iraq sized project anymore without a greater degree of international participation.