Rupert Cornwell: Chalk and cheese – but they're getting friendlier

David Cameron – David who? Thus might be summed up the average American's view of Britain's current Prime Minister. The fault is not Mr Cameron's own. It reflects two facts: the scant attention this country pays to things foreign except at times of crisis, and the fact that no such crisis has propelled him to centre stage.

It was different for two of his recent predecessors. Margaret Thatcher and Tony Blair were household names in the US, the former because of her warrior style and bond with Ronald Reagan, the latter as a result of his partnership with George W Bush in the 2003 Iraq invasion.

At one point, Mr Blair virtually replaced the verbally challenged Bush as explainer-in-chief of the war to the American domestic audience. By the time they left office, both he and Mrs Thatcher were far more popular in the US than back home. By contrast, Mr Cameron has barely impinged on public consciousness here. The closest he's come is as author of the austerity strategy to bring down Britain's budget deficit, its fate closely watched by the US economic community as harbinger of what might happen here after the 2012 election.

But in its own way, the relationship between this Prime Minister and President is developing quite well, even though at first glance, they are chalk and cheese: the Old Etonian Prime Minister and the black American president once supposed to hate the British, the colonial masters who tortured his Kenyan grandfather.

With his cool, analytical and rather distant style, Mr Obama has made few obvious close friends among foreign leaders during his three years in the White House. Right now, Mr Cameron may be as close as they come. The pair talk by phone every couple of weeks or so. Their dealings are said to be "transactional", in the sense that they both like getting things done, reasonably and amicably, with the minimum of fuss.