Must read: The big lie: Andrew Wilkie's job was to find links between Iraq and terrorism. What he found was that the truth counted for little.

"I can't recall precisely the origin of my decision to betray my Government. Probably it was during November and December 2002, when I prepared the detailed intelligence assessment for the Australian Government of the possible humanitarian consequences of the looming invasion of Iraq. It was a sobering experience, one that left me with a clear sense of how bad the fallout from the war could easily be.
The assessment of the British Government seemed particularly weak, not least because of the way in which serious gaps had been backfilled with reams of allegations that I knew couldn't possibly be supported by hard intelligence.
By early 2003, as part of my work at the Office of National Assessments (ONA), I was spending considerable time trawling through the vast intelligence database on Iraq so as to be ready to help cover the war once it started.
What jumped out at me was that the war had little to do with weapons of mass destruction and almost nothing to do with al-Qaeda. We were on the cusp of waging an unjustified war on the basis of a preposterous lie. Importantly, my work with ONA on transnational issues, such as people smuggling, had exposed me to some raw intelligence of very poor quality, which gave me a more critical eye in general when it came to analysing intelligence information. BY LATE 2002 nothing could stop the countdown to war. . . .
Blair and Howard knowingly recycled the US's case for invading Iraq so as to stay in step with Bush. They understood the broader US agenda and were sympathetic to much of it.
Although Howard had clearly decided by late 2002 to support Bush's war, this decision was not a formal decision of Government. Rather it was an understanding of the US's intentions and a determination to support them, at any cost. In this sense, Howard is correct in saying, as he has repeatedly, that no decision was made by the Government to support the war until just before the invasion began. . . .
Howard (and by his own means, Blair) knew before the war began that the US was intent on invading Iraq for many reasons, not only those involving WMD and terrorism. I recall numerous ONA assessments that explored the machinations in Washington and the thinking of George Bush and his circle.
If this knowledge is juxtaposed with the public case for war that was made in London and Canberra, something very interesting is revealed: Blair and Howard's oft-repeated justifications for going to war were quite hollow. Their statements about WMD and terrorism were made in the full knowledge that such justifications were not the central reasons for the US's actions. . . .
On balance the strong, unambiguous language contained in the case for war seemed more the work of salespeople than professional intelligence officers. The claims that the repeated assertions reflected accurately the views of national intelligence agencies are plainly wrong. They were simply too much at odds with the piles of intelligence material I was privy to. In all the material I saw on Iraq, never did I see such a string of unqualified and strong judgements as was contained in the official case for war presented by Bush, Blair and Howard.
By late 2003, however, there was no possibility that Bush, Blair and Howard were unaware of the true situation in Iraq or that they were in some form of understandable denial. No, they were well aware of the fix they were in, but decided to deal with it with more prevarications, fabrications, distortions and exaggerations. Lies beget lies, as they say."