The question is often asked, and is being asked even more frequently now that things are getting rough in Iraq: Why has Tony Blair hitched his wagon to that of George Bush and the Republican Party?
Bush and Blair: More than just cosy
On the face of it, a moderate left of centre British Labour Party prime minister who was a pal of the Democrat leader Bill Clinton has little in common with the born again conservative Republican president.
Even less so when you consider the kind of figures who surround Mr Bush.
The option was open to him to do what the then British Prime Minister Harold Wilson did with President Lyndon Johnson over the Vietnam war.
He did not publicly criticise the Americans but did not send troops. Tony Blair is not however Harold Wilson.
And yet, going back to an earlier Camp David meeting shortly after Mr Bush was elected president, the signs were there that Tony and George would be an item as much as Tony and Bill were.
The British side was impressed at how calm the president was... Here, they felt, was a man of reason as well as determination
They made a joke at the news conference they held - in shirt sleeves on that day, not in the suits they wore after their latest talks - that they used the same brand of toothpaste.
It became a symbol of their closeness.
The British ambassador in Washington at the time, Sir Christopher Meyer, who had been to Texas to see George Bush when he was still governor, became a fan of Mr Bush as well.
He and Tony Blair saw in the new American president a more thoughtful man than the media caricature had suggested.
They believed their assessment to be confirmed after the attacks on New York and Washington of 11 September.
Christopher Meyer recounted later how on the evening of 20 September, before President Bush went to Congress to deliver his "war on terror" speech, the two men spoke in the White House.
Blair in Kosovo before the Americans
The British side was impressed at how calm the president was, and how he readily agreed that there should be no attack on Afghanistan until there had been an ultimatum to the Taleban.
Here, they felt, was a man of reason as well as determination.
The following weekend, again at Camp David, Mr Bush ruled out an immediate attack on Iraq.
Those events, and the subsequent decision by George Bush to go to the Security Council over Iraq, have fed Tony Blair's belief that the American president is not a Texas cowboy.
'Visionary and opportunist'
But that in itself is not enough to explain Tony Blair's position.
A large part of the answer to the question lies in his own character.
There is a visionary side to Tony Blair which cannot be underestimated
Those who are surprised at his role over Iraq should remember what happened four years ago over Kosovo.
It was Tony Blair who was pressing for ground troops - 50,000 British soldiers if necessary - to be sent into Kosovo if the bombing campaign against Serbia failed to move the then Yugoslav leader Slobodan Milosevic.
He was way out in front of the cautious Mr Clinton.
There is a visionary side to Tony Blair which cannot be underestimated. After all, he revolutionised his own party.
He talks about right and wrong. And he has staying power.
A columnist for the London Times, Michael Gove, compared him to William Pitt, who fought against Napoleon.
"He is the pilot who weathered the storm. Tony Blair may not appreciate the comparison with William Pitt but the prime minister is a leader who has seen through a war and emerged with his international reputation enhanced," wrote Gove two years ago.
Michael Gove now says that events since 11 September have enhanced Tony Blair's role with the Americans and have shown that he is "neither a geopolitical gnat nor a poodle".
Others however see a more opportunistic side to Tony Blair, a leader who has cosied up too close to Russian President Vladimir Putin, and who has all but ignored what is going on in Chechnya.
There is also the suspicion that Mr Blair likes to be a figure on the world stage which he could not be if he settled quietly into the conformity of a common European foreign and security policy.
He is also seen as an American salesman.
Nelson Mandela dismissed him with the comment: "He is the foreign minister of the United States."
The war is going to test the relationship.
There are tensions about the exact role of the United Nations in a future Iraq, over contracts for reconstruction, over American reluctance to press Israel to make concessions to the Palestinians.
Major decisions lie ahead about the conduct of the battles and Mr Blair's voice might have to be raised in order to be heard.