Former Director General of MI5, Britain’s internal security service, Baroness Eliza Manningham-Buller described the invasion of Iraq as a mistake on Tuesday, noting that the attack had exacerbated the terrorist threat to the country and was a “highly significant” factor in how “home grown” Muslim fundamentalists justified their actions.

Manningham-Buller told the Chilcot inquiry that Britain’s role in the Iraq War “radicalized, for want of a better word, a whole generation of young people — not a whole generation, a few among a generation — who saw our involvement in Iraq and Afghanistan as being an attack upon Islam.”

In Iraq itself, Al Qaeda was able to gain a foothold, the former intelligence chief declared, because of the invasion. Before March 2003, MI5 “regarded the threat, the direct threat from Iraq as low,” she said. Indeed, “there was no credible intelligence” proving any sort of link between Saddam Hussein’s regime and Al Qaeda — “and that was the judgment, I might say, of the CIA.” It was not a judgement that found favor in Washington however, “which is why Donald Rumsfeld,” the American defense secretary at the time, “started an intelligence unit in the Pentagon to seek an alternative judgment.” Too much was made, according to Manningham-Buller, of “tiny scraps” of intelligence that might sustain a link between Al Qaeda and Iraq.

Once the coalition had invaded, the terrible mistake was made to displace Iraqi officers and Ba’athists from power who, in large numbers, subsequently joined or led the insurgency. Baroness Manningham-Buller said that she had tried to persuade US Deputy Secretary of Defense Paul Wolfowitz from making this colossal error but that there had been “not a hope” of converting him.