Thanks to Spinwatch, I've come across a brilliant new piece of analysis by John Prados of the US-based National Security Archive, which describes itself as "An independent non-governmental research institute and library located at The George Washington University".

Prados has posted online an early draft of the US government's published White Paper on Iraq's weapons of mass destruction programs. The draft was produced in July 2002, while the White Paper was published that October. Although the White Paper was claimed to be a distillation of the US government's National Security Estimate, it is now clear that it pre-dated it.

Prados compares the versions of the White Paper and compares the process with the UK government's dossier, of which an early draft was dated June 2002. He draws the conclusion that the two governments were colluding at that point to put the case for war. He also describes the politicisation of intelligence, taking issue with the Bush administration's claim that "intelligence failure" was responsible for its false claims about Saddam's non-existent weapons of mass destruction. While "a real intelligence failure did occur", this

was abetted and magnified by the Bush administration’s drive to use charges about alleged Iraqi WMDs as justification for war.

Prados also refers to the latest report from the Senate Select Committee on Intelligence, which makes a point that the Butler review really didn't get, that overstating certainty is going beyond intelligence:

In most of these cases the SSCI study found administration claims “substantiated” by the available intelligence but portraying the data as more certain than it was, thus going beyond the intelligence, while failing to convey disagreements among intelligence experts.

Finally, he makes a point about the parallel processes:

The preparation of white papers on both the United States and British sides also needs to be taken into account. That Bush and Blair each turned to their intelligence agencies for the papers is significant—they were evoking the imprimatur of secret intelligence to justify policy preferences. Both papers had the function of justification, not analysis, and neither government waited until it had compiled all the evidence before demanding these products. Neither government asked for intelligence estimates, fashioned in secret, in order to inform policy on Iraq. Instead, both Bush and Blair did want their intelligence agencies to carry out avowed political agendas.