via PLA, I came across this excellent piece by Cogent Provacateur which analyses pro-Invade arguments in a comprehensive and systematic manner. It also obsoletes my attempt to solicit a similar set of bullet points from SDB and others, but it looks at them in a different way than I was intending to. Its a fantastic summation of the debate (one-sided though it is at the moment in the media). He sums up as follows:
Summing up, what have we got? For the administration's true reasons it's not clear ... my "serious" list includes the potential threat to Israel, the sanctions quagmire exit strategy, the assassination attempt, the plunder and transformation arguments, and the Freudian angle. For (informed) US public consumption: Israel, broken promises and UN credibility (especially targeting coalition aircraft), and assassination. For the international market: UN credibility. [Brilliant stroke! Bush outmaneuvered everybody ... maybe even himself!] For the timing and urgency: politics, pure and simple, down and dirty.
but it is extremely worth your time to read the (length) piece in full for its detailed analysis of each of the individual arguments.
CP also has another excellent piece entitled "A Convergence of Parallel Li(n)es" which takes a look at the role propaganda has played in the "debate".