The attacks, he said, made it necessary to "draw a line in the sand here, and the country to do it with was Iraq because they were in breach of UN resolutions going back over many years."

Sitting on a stone terrace overlooking the garden of his Downing Street residence, Blair reflected on how Sept. 11 convinced him of the need for a new approach to the threat of international terror.

"9/11 changed the whole picture for me, it changed the politics of how we dealt with the threat," he said.

He said his actions were based on personal conviction not in the hope of any quid pro quo on other issues, such as climate control, Africa aid, or the Middle East, as some have suggested.

"As I always say to people, my support for America is not based on, you know, 'You give us support on this, and you get that in return,'" he said. "I should only do what is right for Britain, and the president should only do what is right for America."

Despite his strong linkage of the Iraq campaign to the Sept. 11 attacks, Blair denied that the decision to go to war had been fixed long before it was carried out. He said the so-called "Downing Street memos," which suggest the Bush administration had made up it mind to invade by 2002, painted a distorted picture.

"People say the decision was already taken. The decision was not already taken," he said.

According to the minutes of the meeting where the leaked memos were taken, Sir Richard Dearlove, then chief of Britain's intelligence service, said the White House viewed military action against Saddam Hussein as inevitable following the Sept. 11 attacks.