Jcustis - Gaddis did indeed understand before the invasion the 'democracy domino' theory at play. Not surprising as he is very astute (and always worth reading vice US strategy), plus this goal was, as I mentioned, out there in the public domain. But it was obscured as the Bush administration officially focused on three reasons: WMD, Hussein's links to terrorism, and the [humanitarian] liberation of the Iraqi people from an oppressive regime. Wolfowitz in an interesting interview with a Vanity Fair reporter (in late May or early June 2003) noted these three reasons, and said that for 'bureaucratic reasons' the admin focused on WMDs (he did not say what these bur reasons were but my guess is that it was the one which would convince the American public to support the invasion). Intriguingly, in the full transcript of the interview, he then starts to discuss a '4th' reason, in which he appears to start to say that the transformation of the Middle East was a goal; however, the interview is ended there and he never finished.

As everyone knows, once it was evident there were no WMDs (or links to terrorists, Mr.Cheney's favourite reason), the Bush administration shifted to arguing that the US goal was to 'Democratize' the Mid East - which made this reason appear to be a post hoc rationalization rather than it being one of many reasons that had always been present in the administration's thinking.

Also, in my typical absent minded way, one book I would highly recommend on that period but I forgot to note, is: Ivo H. Daalder and James M. Lindsay, America Unbound: The Bush Revolution in Foreign Policy (Brookings Institution, 2003). Not about Iraq per se, but the authors capture well the shift in US foreign/security policy that serves as a framework for some of the thinking vis a vis invading Iraq.

MikeF - Gaddis also understood point G. As Jcustis mentions, Gaddis also recognized the role that preemption played. I focused in G on the impact of the invasion on Iran and Syria but for the US to engage in a preventative attack against Iraq sent a clear signal to any state that the US had the will and conventional military means to deal with anyone it perceived as a potential threat (as long as they did not have nukes), and members of the Bush Admin understood this. As an aside, of sorts, in the aftermath of the invasion Kim Jong-il vanished from public view for a number of months, resulting in speculation that he had gone into hiding fearing that the US would be after him next (that the US would attack N Korea is extremely dubious, as it seems to me the US, no matter which Admin, would be deterred by N Korea's capability to inflict massive human and physical destruction on Seoul by conventional means - there are, IIRC, over 10,000 N Korean artillery tubes able to strike Seoul).