The decision by the US and UK to invade Iraq in 2003 was met with condemnation around the world at the time - and is still haunting its principal architects.
After 9/11 ... nobody in the international community disagreed at that stage that Saddam [Hussein] 'posed a threat to international peace and security'.... These were agonising decisions, but we made the decision [to intervene in Iraq] in good faith ... and on the best evidence that we had .... What would have happened had we not taken the action we did ... Iraq wouldn't have been a picnic, far from it.
On the British side, it was Prime Minister Tony Blair and his Foreign Secretary Jack Straw who took their country to war. Ever since, there has been an intense debate about why they did so.
The long-awaited culmination of an official British investigation should bring insights into how Blair and Straw reached their decision.
The Chilcot Inquiry, named after its chairman Sir John Chilcot, will reveal its findings in July, seven years after it began its work.
Leaks from the final report, which is 2.6 million words in total, suggest that both the prime minister and foreign secretary come under severe criticism.
Jack Straw was a key witness at the Chilcot Inquiry, where he insisted that he supported an attack on Iraq for good reasons: to destroy Saddam Hussein's weapons of mass destruction.
But the evidence that Saddam Hussein possessed such weapons was hotly contested at the time, and was shown to be false after the invasion.
"Of course I regret the fact that the basis on which we made the decision, which was that there were extensive holdings of what we knew Saddam had had, holdings of very dangerous chemical and biological weapons, were not found," he tells Al Jazeera.
Jack Straw stayed on in the British Parliament until 2015. He is now campaigning for the UK to remain in the European Union in the referendum on June 23, and also lectures on international relations.
On this episode of Talk to Al Jazeera, the former UK foreign secretary talks about Turkish-Iranian relations, Western intervention in Syria's war; the threat of ISIL; Tony Blair's legacy; and the issues behind the "most difficult decision of his life" - the invasion of Iraq.
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Source: Al Jazeera