As well he might be - but with provincial elections just 24 hours away perhaps we will learn at last that Iraq can do better without us:
The former Prime Minister insisted he was not haunted by the decision. But he added: "I reflect on it, and am troubled by it, and feel a great sense of responsibility for it."
Mr Blair told The Times: "The most difficult thing in any set of circumstances is the sense of responsibility for people who have given their lives and fallen - the soldiers and the civilians.
"If I did not feel that, there really would be something wrong with me, and there is not a single day of my life when I do not reflect upon it... many times. And that's as it should be.
"On the other hand, you have to take the decision and I look at the Middle East now and I think, well, if Saddam and his two sons were still running Iraq how many other people would have died and would the region be more stable?"
In total there have been 4,551 coalition deaths - 178 of them British service personnel - as well as civilian casualties estimated at anywhere up to a million.