Following Charles Duelfer's final report, the Iraq Survey Group has concluded physical examination of Iraq for weapons of mass destruction. The left will gloat over this and has; Glenn Reynolds spent some time discussing the news' meaning with readers. As many of them argued, the rightfulness of liberating Iraq remains undamaged.
The phrase "Dispensing with WMD was a tactical retreat in [Saddam's] ongoing struggle," from Duelfer's own transmittal message, is one opponents of liberation will have to wrestle with. It is the strategic threat the United States would have continued to face, alongside the perpetuation of Oil-for-Food money-hoarding and the maturation of al-Qaeda and Iraqi Intelligence Service ties. So much for "containment."
Many supporters of Iraq's liberation did indeed publicly observe that Bush and Blair's United Nations drive focused too heavily on the WMD case, especially because it remained morally neutral on the question of Iraq's polity. Logically, if Saddam could have proven his disarmament beyond France's, Russia's, Germany's and China's doubts, he could have been left to his own like Gadhafi. On one hand, from what we know now that would have allowed Saddam to shunt his capital into crash programs. On the other, it means the WMD angle was a relatively weak one — which is why it's a favorite of the reactionaries.
But because of that moral neutrality, there's a flaw in the left's charges. If one wants to discredit the president's justifications for deposing Saddam Hussein based on the nature of Iraq's WMD as revealed post-Saddam, then one can't go on to discredit his justifications based on the occupation and reconstruction. The time, effort, money and sacrifice invested in the latter — Bush's "idealism," mocked by his critics — sunders the notion that Operation Iraqi Freedom's case rested on the former.
Thankfully, the right is quite used to the left not making much sense.