George W Bush's administration saw Iraq as "unfinished business" and had their "minds made up from day one," a former CIA analyst has said.
John Nixon, who questioned Saddam Hussein after he was found hiding in a cave in December 2003, said the Iraqi dictator's death warrant was signed after the 9/11 attacks.
Discussing the first days of the Bush administration on BBC Radio 4's Today Programme, Mr Nixon said: "We had gotten word that they saw Iraq as 'unfinished business'.
"We never really understood at that point what unfinished business meant, but we knew that they wanted to do something."
He added: "You know, they had their minds made up from day one. And then after 9/11, that's when the death warrant for Saddam Hussein was signed."
The CIA interrogator has previously said it quickly became clear Mr Hussein had not developed weapons of mass destruction when he questioned him.
He has also spoken out against the Iraq war numerous times, saying America was critically mistaken about the intervention in a number of ways.
Mr Nixon also said the execution of Mr Hussein was "the final straw in terms of pulling out the justifications for the war in Iraq."
He described it as "a mob justice" and said "Saddam was the most dignified person in the room."
Mr Hussein was executed in 2006, three years after he was captured close to his home town of Tikrit.
Commenting on the infamous unauthorised video of the execution, he added: "I was blown away by the video. I was shocked by it and disgusted.
"We went to Iraq to do all of these things, to find the weapons of mass destruction, to help build a new Iraq, to establish rule of law, give the Iraqi people democracy, and one by one, all of those things just crumbled."
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