Note to liberals who reach across the aisle: you give an inch, they take a mile.
Most liberals I know did indeed expect an easy win against Iraq. We have the most powerful military in history (Bush's false accusations of "not ready to serve" in the 2000 campaign notwithstanding) arrayed against the sanctions-decayed, conscript-fueled, politically incestous ragtag army that never really recovered from the first Gulf War, let alone the sapping 12-year war against Iran.
But as Michael Kinsley points out, the easy military victory does not justify the decision to attack. That is circular logic. The rationale for war has always been the weapons of mass destruction, but there has been essentially zero evidence that Iraq posessed any capability to even threaten Israel, let alone the US. My own argument against the war pointed out that the threat from Iraq WMD (N, B and C) was essentially zero, and that posited the existence of such weapons. I was as surprised as anyone that there turned out to be none.
And what about liberation? I've been as pleased at the fall of Saddam as anyone. But while liberation was a necessary argument to justify war, liberation alone is not sufficient.
And the postwar battles have yet to be fought - the power/authority vacuum left behind by Saddam's fall has exacted a terrible cost to all of humanity, which I think was a function of this particular route to war.
Triumphalist hawks bear the moral burdens for these responsibilities, not I.
 Gary Hart and Lawrence Korb also debated military readiness in Slate back during the 2000 campaign, excellent reading. GOP arguments that the military was underpaid by Clinton were also false. Compare and contrast with how thinly stretched and under-funded our military is today, via Nicholas Confessore in The Washington Monthly.
 Excellent article, has been posted to the UNMEDIA list. The list archives are public, open to non-subscribers for browsing and searching.