After 69 days in which international issues have taken a back seat to attempts to rescue the economy at home, President Obama takes the world stage this week as a wildly popular figure among the people of Europe, but one who faces a difficult task in selling his plans to the continent's leaders.
The president plans to push for a new approach to the war in Afghanistan, aggressive action to stop the proliferation of weapons and a more united European effort to combat the global recession.
But if the U.S. president thought his popularity would cause foreign governments to fall quickly into line behind a new American leadership, experts warn, he could be in for a rude awakening.
The German government has resisted calls to deploy more combat troops to Afghanistan. Russia is pushing back against a NATO missile defense system in Poland. And the Czech prime minister last week described the U.S. plans for global economic recovery as the "road to hell."
On Saturday, the White House made clear that it is not trying to dictate spending in European capitals to revive the economy, after facing strong resistance from France, Germany and other nations.
"The notion that Europe is going to rally around this administration is being exploded," said Nile Gardiner, director of the Margaret Thatcher Center for Freedom at the Heritage Foundation. Gardiner predicted "a rapturous welcome" for Obama from the European public but said that "when it gets down to the discussions . . . there are going to be very tense discussions."
Obama's election was heralded by many European leaders as a clean break from the administration of President George W. Bush, who angered many in foreign capitals with what they viewed as slight regard for their input. They saw Obama's Republican predecessor as reckless and too willing to act without first achieving consensus.
White House officials describe Obama's trip as a way of confronting those "inherited challenges" left over from the Bush administration, and they said they expect the three summits he will attend to produce broad agreement on new approaches to economic recovery, fighting terrorism and securing peace in unstable regions.
"We think [the trip] is obviously going to be a fundamental part of the president's agenda of restoring America's standing in the world, and particularly in Europe," said Denis McDonough, deputy national security adviser for strategic communications.
Longtime observers of cross-Atlantic presidential trips say Obama retains much of the star power he exhibited during his campaign swing through Europe last summer, when he delivered a speech to more than 200,000 people in a German square.
"It's still a case that European leaders want to be seen next to Obama, preferably with Obama, his arms around their shoulders and a big smile, because he's so popular in Europe," said Reginald Dale, a senior fellow at the Center for Strategic and International Studies.
But replacing Bush with Obama has not erased the substantial disagreements that remain between the United States and Europe.
"That's an invitation to disillusionment," said Sen. John F. Kerry (D-Mass.), chairman of the Senate Foreign Relations Committee. "These are complicated times. There's an anger in the world . . . about how people think our country has helped create these problems. The president has to lift heavily to get us over the Bush hurdle."
Throughout the presidential campaign, Obama's rivals repeatedly questioned whether his youth and relative inexperience would make him a pushover when he came face to face with world leaders.
Obama's mission now is to lay those doubts to rest, in part by making good on his campaign promise to improve the sometimes-strained relations with U.S. allies.
Aides point out that Obama has been engaged in that effort since he took office, calling world leaders almost daily. Last week, he discussed his trip and the global economic crisis with French, German and British leaders, among others.
Between dealing with economic crises, Obama has made moves that have been generally well received across the Atlantic: ordering the detention facility at Guantanamo Bay, Cuba, closed; announcing a drawdown of U.S. forces in Iraq; and crafting a new policy for dealing with Afghanistan and Pakistan, which he announced Friday.
"This is his first major multi-lateral summit," said one senior foreign policy adviser. "But he's been working the issues all the way back to the transition."
Michael Froman, Obama's deputy national security adviser for international economic affairs, said the president plans to "lead by example," offering his actions domestically -- including a stimulus package, regulatory reform, housing proposals and financial stability plans -- as motivation for global action.
"He's going first and foremost to show U.S. engagement to the rest of the world. Be open-minded, listen, but also to lead, lead by example," Froman said.
The question is whether that will be enough to create enthusiasm among leaders faced with their own struggles.
Obama's counterparts are grappling with economic crises at least as severe as the one in the United States. That has led to political instability throughout much of Europe that complicates Obama's upcoming meetings.
Governments have collapsed in Latvia, Estonia, Hungary, Iceland and, most recently, the Czech Republic, where Mirek Topolanek, the prime minister, lost a vote of no confidence. Topolanek serves as the president of the European Union and is expected to remain the host for the organization's summit in Prague today despite his political problems.
"[Obama's] problem is that everyone is weak. His main allies are very weak. Even his rivals are weak," said Moisés Naím, editor in chief of Foreign Policy magazine. "In the weakness of rivals loom large risk."
The danger, Naím said, is that European leaders are in no position to deliver what the United States wants on the economy or security issues, despite their desire to please the U.S. president.
In addition, Naím said, many of the foreign leaders have their own domestic reasons to pick a fight with the new American leader, if only to show that they are not bowed by his celebrity.
That could be particularly evident when Obama holds a one-on-one meeting with Russian President Dmitry Medvedev in London.
"Medvedev also has to show that he is as tough as [Prime Minister] Vladimir Putin," Naím said. "The 500-pound gorilla that's not in the room is Putin. Everyone knows, and Putin makes sure that everyone knows, that he calls the shots."
Still, Obama and Medvedev are expected to reach an agreement that could lead to a new arms reduction treaty between the two nations. The 1991 Strategic Arms Reduction Treaty expires at the end of this year.
In Prague, Obama will make what aides describe as a "major address" on the proliferation of dangerous weapons. At a summit of NATO leaders, Obama will urge a modernization of the alliance to better fight the security threats from terrorists and rogue nations.
And at the summit of the Group of 20 major economies, he will call for a new approach to reviving the global economy through government spending, tougher regulation of financial institutions and an embrace of free trade.
In between, the White House promises a series of one-on-one conversations with the leaders of Turkey, Spain, Saudi Arabia, South Korea, China, India and Britain. On Wednesday, Obama will meet privately with Britain's Queen Elizabeth II. In Istanbul, he is expected to hold a global, video-based town hall meeting that will allow students from across Europe and Asia to ask questions.
"This is a real test of his leadership," Dale said of the eight-day, five-country trip. "Particularly, I think, in the economic section, where the whole world is suffering and there's a real opportunity for the president to show global leadership."