Butler review

The Butler Review was established following the failure to find stockpiles of weapons of mass destruction (WMD) in Iraq after the invasion. Lord Butler’s team—which included MPs and senior intelligence figures—was tasked with investigating why the pre-war intelligence was so wrong. The inquiry sat in secret to protect national security, but its final report was a watershed moment for the British intelligence community.

The report’s most famous conclusion was that the government’s 2002 dossier had been presented in a way that gave an "impression" of certainty that the underlying intelligence did not support. Butler found that the Secret Intelligence Service (SIS/MI6) had failed to properly validate its sources, some of whom were "third-hand" or unreliable Iraqi dissidents. He described the "creeping tide of proliferation" where caveats in original intelligence reports were slowly stripped away as they moved up the chain of command, a process he called "groupthink."

Specifically, the review criticised the "45-minute claim" (that Iraq could deploy WMDs within 45 minutes), stating it should not have been included in the dossier without clarifying that it referred only to battlefield munitions, not long-range missiles. However, the report did not "sink" the government. It explicitly found no evidence of "culpable negligence" by the intelligence services and no evidence that the Prime Minister, Tony Blair, had lied. Lord Butler concluded that John Scarlett (Chairman of the Joint Intelligence Committee) should stay in his post, much to the anger of anti-war campaigners.

The legacy of the Butler Review was a total overhaul of the Joint Intelligence Committee (JIC). It led to stricter rules on how intelligence is "caveated" when shared with politicians and ensured that the "authorship" of public dossiers must be clearly attributed to the government, not the intelligence agencies, to avoid blurring the lines between spy-craft and political advocacy.