Can President Obama lead the world? That may overstate the ambitions Obama will take with him to Europe Tuesday for a week-long series of summits and speeches. But it is the question that will shadow him throughout his trip and likely become the basis for judging the outcome once he returns.

Candidate Obama promised Americans a fresh start with the rest of the world, after eight years in which former President Bush’s policies and style made this country deeply unpopular abroad. Before he was even serious about running for president in 2008, Obama had concluded from the reaction he received on a trip to Africa in the summer of 2006 that his election had the potential to change instantly international perceptions of America.

That seems indisputable. As a leader Obama is significantly more popular overseas than Bush ever was. The question is whether Obama has a strategy in mind to leverage that popularity to bend recalcitrant allies in directions he would like them to go, whether that means producing a coordinated response to the international economic crisis or winning concrete support for his new policies for Afghanistan and Pakistan.

Implicit in Obama’s campaign rhetoric was that he would seek cooperative relationships with America’s allies, rather than pursuing the unilateral style that often marked Bush’s approach, particularly in his first term. Stylistically that should make him a more appealing U.S. leader to his counterparts in Europe and elsewhere. Substantively, it leaves considerable power in the hands of U.S. allies to resist measures Obama may be advocating, unless he proves to be powerfully persuasive in both public and private venues.

Last summer, Obama got his first taste of this when he took his week-long trip to Iraq, Afghanistan, the Middle East and Europe. Because he was there as a candidate, he was not selling a particular set of policies. Mostly he was trying to make a good impression on leaders with whom he might be dealing and to win an election back home. But at the end of the trip he talked about the potential value of having a president who enjoys the good will of publics in countries around the world.

One of the central debates of the campaign, he said, was over which candidate was best positioned to forge coalitions that could successfully deal with big issues, from terrorism to climate change to the economy. “What I thought was useful was to give the American people some sense of how I was approaching these issues, but also to give them a sense that the world can be responsive to this approach and that it will make a difference,” he said that week.

At the time, he used Afghanistan as an example of how an Obama presidency might succeed where Bush’s had failed. He was already advocating the need to send more troops to Afghanistan and for troop support from other countries. Leaders in those countries, he argued, would be more likely to cooperate if their constituents were more favorably disposed toward the United States and its president.

“Anti-American sentiment is not useful even when we’ve got strong allies like [German Chancellor Angela] Merkel and [French President Nicolas] Sarkozy, who are pro American and favorably disposed and don’t engage in, you know, sort of taking cheap shots at us. They’ve been great allies. But we put them in a tough bind if we’re not attentive to their constituencies. So I wanted to give voice to that very practical, hard-headed approach to foreign policy.”

Obama’s July trip was a trial run. There was no political payoff likely at the time. The only real risk was that he might commit a gaffe that would undermine his hopes of winning the presidency.

His advisers argued at the time that the real value of spending a week abroad in the middle of a campaign would come only if he won the election. He would start his presidency having taken the measure of a number of key world leaders (and they of him) and would need no on-the-job training once in office.

All of that will be put to the test this week, under circumstances that are significantly different than they were last summer, given what has happened to the world economy. It should be easy for Obama to escape any blame among Europeans for Bush’s national security policies. He can begin his Afghanistan policy with a relatively clean slate – though that will not assure that European allies will step up.

On the economy, it will be less easy for Obama to insulate himself from anger abroad that American-style capitalism (and lack of government regulation) trashed the world economy, though European-style capitalism (and government) bears responsibility for the current crisis as well. Obama may bear no direct responsibility for what happened before he came into office, but perceptions of cowboy capitalism may complicate his ability to forge the kind of consensus or coalition he talked about last summer.

Obama has demonstrated that he can command attention on the world stage and no doubt will do so again this week. How much that attention translates into influence on the other leaders with whom he will be meeting will determine whether the president’s first big foreign journey meets the expectations he set as a candidate.Obama Progress