When he describes the virtues of Clinton, Bush and Obama it is hard not to think that Blair is measuring himself against these occupants of an office that he describes as inspiring a “certain awe” among “mere mortals”.

More self-disciplined that Clinton, more analytical than Bush and more practical and centrist than Obama, there is a case to be made that Blair is a greater all-round political talent than any of these three most recent occupants of the Oval Office.

There was briefly a jocular “Tony Blair for President” campaign in 2004. He would, of course, be prevented from running for the White House, even if he one day became a citizen, because he was not born in the US.

Yet as Blair prepares to step up his role as globetrotting statesman with, no doubt, plans to spend more time in America, he seems to reflect with a certain rue that the US would have been the perfect stage for him.