An interesting site is After Downing Street which is attempting to, among other things, publicize the Downing Street memo from July 23, 2002. One reason why this memo is important is because it is one of the earliest documents showing how determined Bush was to invade Iraq. Posturing in the UN over the next months was essentially just that: posturing. Here's a damning bit from the memo:

C reported on his recent talks in Washington. There was a perceptible shift in attitude. Military action was now seen as inevitable. Bush wanted to remove Saddam, through military action, justified by the conjunction of terrorism and WMD. But the intelligence and facts were being fixed around the policy. The NSC had no patience with the UN route, and no enthusiasm for publishing material on the Iraqi regime's record. There was little discussion in Washington of the aftermath after military action.

CDS said that military planners would brief CENTCOM on 1-2 August, Rumsfeld on 3 August and Bush on 4 August.

The two broad US options were:

(a) Generated Start. A slow build-up of 250,000 US troops, a short (72 hour) air campaign, then a move up to Baghdad from the south. Lead time of 90 days (30 days preparation plus 60 days deployment to Kuwait).

(b) Running Start. Use forces already in theatre (3 x 6,000), continuous air campaign, initiated by an Iraqi casus belli. Total lead time of 60 days with the air campaign beginning even earlier. A hazardous option.

In case you're not familiar with the phrase casus belli, it is "widely used to simply mean a nation's motives for going to war, without reference to any formal documents or proposed means of redress, and sometimes without even implying that these motives are just." I'd interpret the "Iraqi casus belli" as being a trumped up or provoked reason by the US and it's allies. I mean, how can you expect the Iraqis to suddenly give you a reason to attack on cue?

Go visit these folks. "[After Downing Street] is a coalition of veterans' groups, peace groups, and political activist groups, which launched on May 26, 2005, a campaign to urge the U.S. Congress to begin a formal investigation into whether President Bush has committed impeachable offenses in connection with the Iraq war."