Christopher Hitchens in Slate, answering his own questions --
Wasn't Colin Powell's performance at the United Nations a bit of a disgrace?
Yes, it was, as was the supporting role played by George Tenet and the CIA (which has been reliably wrong on Iraq since 1963). Some good legal experts—Ruth Wedgwood most notably—have argued that the previous resolutions were self-enforcing and that there was no need for a second resolution or for Powell's dog-and-pony show. Some say that the whole thing was done in order to save Tony Blair's political skin. A few points of interest did emerge from Powell's presentation: ... the presence in Iraq of Abu Musab al-Zarqawi, a very dangerous al-Qaida refugee from newly liberated Afghanistan, was established. The full significance of this was only to become evident later on.
Was the terror connection not exaggerated?
Not by much. The Bush administration never claimed that Iraq had any hand in the events of Sept. 11, 2001. But it did point out, at different times, that Saddam had acted as a host and patron to every other terrorist gang in the region, most recently including the most militant Islamist ones. And this has never been contested by anybody.
His answer to his 2nd quasi-rhetorical contradicts his answer to the first. One of the many complaints about Powell's speech was indeed the reference to Abu Musab al-Zarqawi, because he was only in a part of Iraq not under Saddam's control; he was in the Northern no-fly zone with the terrorist group Ansar al-Islam, the one that Bush decided not to bomb prior to March 2003 to preserve his larger rationale for the Iraq war.
Hitch also seems to think that it's interesting but only esoteric whether the previous UN resolutions were self-enforcing. But that in fact is the formal UK position on the legality of the war.
[Note: the legal basis for the war in previous UN resolutions still doesn't stop Tony Blair from using the regime change justification in public; see also this excellent reader e-mail to Andrew Sullivan]