In September 2002, according to Politico magazine, Donald Rumsfeld received a report (mostly declassified in 2011) stating that the intelligence on Saddam Hussein’s putative weapons programs was essentially worthless. For example, the report says:
Our knowledge of the Iraqi (nuclear) weapons program is based largely—perhaps 90%—on analysis of imprecise intelligence
The report was seen by Paul Wolfowitz, then Deputy Defense Secretary and now an adviser to Jeb Bush, but wasn’t shared with President George Bush, or with other members of the Administration, such as Colin Powell. And despite his musings about known and unknown unknowns (unsurprisingly the subject of some sardonic comment in the Politico piece, Rumsfeld showed no doubt in his public pronouncements about the supposed weapons.
This report ought to be (but won’t be) enough to discredit Rumsfeld and Wolfowitz once and for all. Given that they knew that the claimed legal basis for the war relied on spurious intelligence, both are guilty of the crime of a war of aggression. More to the point, in terms of US political debate, a Defense Secretary who sends thousands of US troops to their deaths in pursuit of a goal he knows to be illusory ought to be condemned out of hand.
On the other hand, does the report help to exonerate those who advocated war based on the spurious intelligence being pushed by Rumsfeld? Not to any significant degree. The fact that Rumsfeld was a four-flusher was obvious in December 2002, when Saddam denied having any weapons. As I observed at the time
In the standard warblogger scenario, the declaration was the trigger. Once it came out, the US would produce the evidence to show Iraq was lying and the war would be under way … Instead, Iraq is denying everything but the US is in no hurry to prove that Saddam is lying … The only interpretation that makes sense is that, despite all the dossiers that were waved about a few months ago – including satellite images of ‘suspect’ sites – the Administration doesn’t really have anything
Anyone who wasn’t already committed to war could have followed the same reasoning, and many did.