Mr Blair and his advisers have been watching the scenes in Baghdad today. All the usual caveats apply, there could be terrorist attacks in the future and all sorts of things could go wrong but frankly the main mood is unbridled relief.
Atmosphere of relief in Downing Street as Baghdad falls to US troops
I have been watching ministers wander around with smiles like split watermelons.
This draws a line under what had been, before this war, a period when a faint air of pointlessness almost was hanging over Downing Street.
He said that they would be able to take Baghdad without a bloodbath
There were all these slightly tawdry arguments and scandals. That is now history.
Mr Blair is well aware that all his critics out there in the party and beyond aren't going to thank him for being right when they've been wrong and he knows there might be trouble ahead.
But I think this is a very, very important moment for him. It gives him a new freedom, and a new self-confidence.
He confronted many critics - I don't think anybody after this is going to be able to say of Tony Blair that he is somebody who is driven by the drift of public opinion, or focus groups or opinion polls. He took all of those on.
Tonight he stands as a larger man and a stronger prime minister
He said that they would be able to take Baghdad without a bloodbath and that in the end the Iraqis would be celebrating, and on both those points he has been proved conclusively right.
It would be entirely ungracious, even for his critics, not to acknowledge that tonight he stands as a larger man and a stronger prime minister as a result.