London: From the war in Afghanistan to a possible conflict against Iraq, Tony Blair has proven to be an unflinching ally of George W Bush by conviction, and by political calculation.

Britain's Labour Prime Minister was the first to extend total and unconditional support to the Republican US President's campaign against terrorism in the wake of the September 11 attacks.

One year on, Blair remains the only major world leader to support Bush's threats of military action against Iraq, an option that the two men will review at Camp David this week.

Close ties between Britain and the United States have, of course, been the norm since World War II.

"But now, against this general background of co-operation, Blair is particularly concerned to remain close to the United States," said Adam Roberts, professor of international relations at Oxford University.

Bush's war on terrorism finds deep resonance with Blair, who as a man of avowed Christian convictions "takes a somewhat moralistic stance with international relations", Roberts told AFP.

It was in the name of morality that Blair pushed for North American Treaty Organisation (NATO) intervention in Kosovo in 1999, and it is because he feels "it is the right thing to do" that he is open to the idea of military action against Saddam Hussein.

Behind this stance is a pragmatic political calculation, that it is better to win Washington's trust in order to influence its decisions, and that Britain is better placed than any other nation to act accordingly.

"There is a tendency in Britain to see itself as the Athens to America's Rome," Roberts said. "It's a rather self-indulgent tendency, because it implies that we are possessor of superior wisdom."

"But I think that there is something to it, especially with the current (Bush) administration that clearly has tendencies to acting unilaterally and is rather impatient with the rest of the world," he said.