Barack Obama's weeklong foreign tour has gone so well for him that the only risk left is a rapturous reception in Europe. At least his critics are hoping to use such a response against him.

Obama's trip hasn't been entirely smooth. In several contentious television interviews, the presumptive Democratic nominee has struggled to explain why he thinks President Bush's troop surge in Iraq was a mistake, even though he praises its results. And Gen. David Petraeus, the top U.S. commander in Iraq, firmly signaled that he will continue to resist Obama's plan to withdraw all American combat forces within 16 months of the start of the next administration.

Yet Obama, who faces doubts from many voters about his commander-in-chief credentials, has looked and sounded confidently presidential as he has met with foreign leaders. And Obama received an incalculable boost when Iraqi Prime Minister Nuri Kamal al-Maliki, after some hedging, reaffirmed his belief that U.S. forces should leave his country by 2010. That wasn't a precise endorsement of Obama's timeline, but it placed Maliki much closer to the Democrat than to John McCain, the presumptive Republican nominee, who has talked about a decades-long American presence in Iraq.

It hasn't hurt Obama that McCain chose this week to uncork another series of verbal blunders (resurrecting, yet again, "Czechoslovakia" and creating an Iraq-Pakistan border) that caused some media outlets to wonder whether the almost-72-year-old was showing his age. In all, Obama's week has gone well enough to justify the verdict of longtime conservative activist William J. Bennett on CNN: "This is a hell of a run he's having."

All that is left for Obama is to enjoy cheering crowds during his trip's quick European leg, which began with his Thursday speech in Berlin. Yet that very adoration--which is reflected in polls showing that the European public vastly prefers him to McCain--may represent the trip's sole remaining political danger for the Democrat. U.S. conservatives are poised to argue that Obama's popularity with audiences abroad ought to raise doubts among Americans at home.

This reprises an argument that Republicans deployed against Democratic nominee John Kerry in 2004. At the GOP National Convention, former New York City Mayor Rudy Giuliani mocked Kerry's claim that he had more support from foreign leaders than Bush did. "To me," Giuliani insisted, "that raises the risk that he might well accommodate his position to their viewpoint." Vice President Cheney, charging from the opposite direction, argued that Bush's international unpopularity demonstrated his determination to stand up for America. "George W. Bush," Cheney thundered, "will never seek a permission slip to defend the American people." The bottom-line message: The more support a candidate inspires abroad, the less Americans can trust him to defend their own national interests.

McCain is unlikely to state the case so baldly, because he has repeatedly pledged to mend fences with allies after the antagonism over the Iraq war. (In fact, Bush has also worked more closely with America's allies in Europe and Asia during his second term.) But some conservatives are already reviving the 2004 arguments. On his radio show this week, Rush Limbaugh declared of Europeans: "They love Obama because he loathes America." Conservative blogger Jennifer Rubin predicted that "the race for international popularity" might prompt Obama to undermine Israel and abandon Iraq.

Could arguments like these hurt Obama? Andrew Kohut, director of the nonpartisan Pew Research Center for the People and the Press, is dubious. Recent Pew surveys have found a slight increase since 2004 (from 67 percent to 71 percent) in the number of Americans who say they think the U.S. is less respected in the world than in the past--and a bigger jump in the share who consider that a major problem (56 percent, up from 43 percent). "More people see the importance of rebuilding international ties than four years ago," Kohut says. And foreign acclaim could help Obama maintain that he is better equipped than McCain to restore those connections.

But fault lines remain. College-educated Obama supporters, when asked why they back him, nearly always insist that his election--as a mixed-race, mixed-heritage president--would transform America's image abroad. I have almost never heard that argument from blue-collar voters, especially blue-collar men, who Pew polls show are the voting bloc least concerned about America's international standing and most supportive of GOP arguments that the best way to ensure peace is through military strength, not diplomacy.

European cheers may strengthen Obama at Starbucks, but it remains to be seen whether they will sweeten his prospects at Dunkin' Donuts.

This article appeared in the Saturday, July 26, 2008 edition of National Journal.

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