When French President Nicolas Sarkozy and his wife, Carla Bruni, sit down for dinner with the Obamas in the White House family dining room March 30, it will be a rare occasion for Barack Obama: a private, personal, perhaps even chatty evening with another world leader.

Fourteen months into the Obama presidency, one striking feature of an American president who took office to a swooning world is the absence of any strong personal ties – or even a go-to working relationship – with any other world leader. Where Ronnie had Maggie, and Bill and even George W. had Tony, Mr. Obama has no one leader. Instead, the former law professor has what seems to be a preference for big-themed foreign speeches (think Cairo; Prague, Czech Republic; Moscow; Accra, Ghana) and policy gatherings (his UN nuclear summit, the Pittsburgh Group of 20 economic summit, a White House nuclear nonproliferation summit in May) bereft of the warm and fuzzy.

A dinner chat with Sarkozy

Even the Sarkozy dinner seems to be more an amendsmaker than a familiar, "Hey Sarko, why don't you come on over for dinner and some one-on-one conversation?" When the Obamas were in Paris last year, Obama turned down a dinner invitation to the Elyseé Palace, ostensibly so he could take Michelle out for a private night on the town.

Obama's cool, all-business demeanor with his global peers is all the more striking because it follows the polar-opposite style of George W. Bush. President Bush's policies were widely reviled overseas, and he was not particularly articulate. But he strove to forge personal links with a few key leaders. He cultivated Tony Blair's friendship on Iraq, and he developed a hierarchy of visit venues – White House, Camp David, his Texas ranch – that signaled where a leader stood in his estimation. He walked hand in hand with the Saudi king, and even tried massaging German Chancellor Angela Merkel's shoulders – although the latter gesture fell particularly flat.

Bush's comment about "looking into his soul" upon meeting Russian President Vladimir Putin suggested a desire to know and understand the leader, whereas Obama has yet to find his soul mate on the world stage – and may not be inclined to find one.

No special relationship

"It really is striking about Obama: Most presidents have had a special or close relationship with a foreign leader they could turn to," says Thomas Henriksen, a US foreign-policy scholar at the Hoover Institution in Stanford, Calif. "But it appears to be his nature or personality, the so-called no-drama-Obama thing."

Others link the dearth of leader-level friendships to Obama's personality as well.

"There is a stylistic difference from George W. Bush that is notable," says Stephen Hess, an expert on the US presidency at the Brookings Institution in Washington. "Obama turns out to be much more cool, in McLuhanesque terms of cool and hot," he adds, referring to the Canadian media philosopher Marshall McLuhan.

The question is, does it matter? Mr. Hess is inclined to play down the importance of what he surmises may be a media fixation, saying leaders in the end act on behalf of their own countries. "Each head of state is ultimately and overwhelmingly operating based on interests" – his own and his country's, he says.

Hess, who served in the Eisenhower White House, recalls that President Eisenhower had "a deep affection" for British Prime Minister Anthony Eden. "But when it came to the Suez crisis [of 1956], he had to cut [Eden] down at the knees. Friendship or no," Hess adds, "he did what he had to do."

But others say leader-to-leader friendships can provide important moral support, a valuable sounding board outside the White House cocoon – and have bucked up more than one president in a moment of crisis.

Thatcher stiffened Bush's backbone

"When Margaret Thatcher told the first President Bush, 'Now don't go wobbly on me George,' it might have stiffened his backbone a little precisely because it was a friend saying it," says Hoover's Mr. Henricksen, referring to a remark the British prime minister famously made to Bush in the run-up to the Gulf War.

Henricksen also notes that French President Sarkozy, who has tried in more ways than last year's spurned dinner invitation to cultivate a close relationship with Obama, has refused to send additional troops to Afghanistan despite the American president's request.

"Who knows if Sarkozy would have made the same decision if he hadn't suffered some of these slights on the part of Obama," he says. "What it comes down to is that relationships do matter."

Some foreign-policy experts see something even deeper in Obama's aloofness toward European leaders in particular.

Is Obama interested in Europe?

"There's a general concern among European leaders that America under Obama is not interested in Europe," says Reginald Dale, a senior fellow in the Europe program at the Center for Strategic and International Studies here. "More striking still is a dawning perception that Obama is the first [postwar] American president not to take on the role of leader of the West," Mr. Dale says. "He's just president of the United States."

But those deeper concerns start with what might seem to be the mundane, Dale says – the lack of a rapport with any Western leaders, a White House "regret" that attending a US-Europe summit later this spring will not be possible, Obama's focus on Asia and his declaration in Tokyo last year that he sees himself as America's "first Pacific president."

Dale says he still has ringing in his ear the words of a senior European diplomat, who recently told him, "[Obama] talks to his enemies. Why can't he talk to his friends?"

Those words struck Dale as a cry of concern rooted in Obama's neglect of America's core allies. "Obama is demonstrating a different vision of the world by paying significantly more attention to China, Russia, and also India and Brazil," he says. "Even in a multipolar world you'd think it would make more sense to have a community of Western allies defending their own interests," he adds, "but you're not going to do that by snubbing your old friends."