It's worth unpacking another element of the debate; and that is what "WMDs" actually meant before the war. I took the shorthand to mean chemical, biological or nuclear material that could be used either as weapons or given to terrorists to use. I think that's pretty much in line with what most people assumed. But we may have been talking past each other. Only recently have I absorbed how so many on the anti-war left and right heard primarily "nuclear" when the term WMD came up before the war. And so we ended up debating different things. The nuclear case was always very weak, but then we had the experience of 1990 in our heads, when we seriously under-estimated Saddam's WMD capacity. Markos Moulitsas, to take a pretty representative sample of the left, was right to question the nuclear part of the equation, but he took the existence of other WMDs for granted before the war:
"Iraq has weapons of mass destruction? Join the line. About a dozen nations have such weapons these days. Only the US has deigned to use them, and that was when it was the sole nuclear power. The threat of annihilation through retaliation has checked any subsequent use of such weapons.
Iraq will give weapons of mass destruction to terrorists? Would the secular Hussein give such weapons to religious fundamentalists? Doubtful. Terrorists are more likely to receive such weapons from Pakistan's intelligence agency — which has deep ties to the Taliban and Al Queda [sic]."
As I said, one of the more vocal arguments against the war was that an invasion was the only scenario in which Saddam would indeed use WMDs. Their existence was a premise of the anti-war case, and their non-existence dramatically reduced the risk of war. And so, while we're playing the hindsight game, the U.S. casualties in this war, however awful, are still way below what most people expected. Here's Kos again, from September 2002:
"Current plans seem to range from 50,000 to 250,000 invading troops. Of those, the vast majority are support troops, so say, 10,000 to 50,000 actually participate in a Baghdad assault. At 10 percent casualty rates, that could mean up to 5,000 US dead. And that's assuming no use of WMD."
I remember fearing up to 10,000 casualties in taking Baghdad alone, so I'm not beating up on Kos. The point is: almost all of us were wrong, (while only a few made truly dumb predictions like 9/11 "will be off the evening news by Thanksgiving"). That's the nature of history. And that, in retrospect, is why conservatives like me should have been more risk-averse, empirical and skeptical in the run-up to war in Iraq.