I was taking pictures alongside other tourists at the Temple of Karnak in Egypt earlier this month when a member of the national police marched across 50 yards of sun-blasted terrace to talk to me. He was wearing the black uniform and beret of the security forces, and he had an assault rifle strapped acoss his chest.
"Where from?" he asked me.
"America," I said.
"Obama!" he shouted, suddenly beaming and nodding.
It might have been startling, except that something similar happened every day of the dozen I was there.
It's a commonplace that President Obama has altered the perception of the United States around the world. But meeting people in an Arabic-speaking country brings that statement to life in compelling ways.
Shopkeepers and cabbies, students and business people, young and old are eager to signal their interest and approval. America, an old and well-known actor on the world stage, has undergone a character transformation overnight.
As one American woman said to me: "I don't have to pretend to be Canadian any more."
It is impossible to escape the sense of something opening all around you. If it is not a new era, it is at least a new window of possibilities. Perhaps the "clash of civilizations" paradigm that dominated after Sept. 11 will not prevail indefinitely.
Yet, alongside that glimpse of hope there are shadows of caveat and doubt. For one thing, the impressions Americans receive in foreign countries are often formed inside a tourism bubble, where people have a strong interest in courting our friendship.
Beyond that, the sheer intensity of the Obama phenomenon suggests impermanence. Having dazzled his way from London to Istanbul to Baghdad, the American president is a starburst over the global consciousness — much as he was on the U.S. political scene late in 2007. He maintained altitude well enough in 2008 to be elected, and he remains popular after three months in office. But staying aloft this well as a world figure will be more difficult.
The international version of the Obama Moment is unlikely to survive the first international crisis in which the Obama administration must defend the U.S. interest. And sooner or later, that crisis and choice will come, forced by the complexities of world problems and the simplicities of domestic politics.
For now, the Obama administration is doing all it can to postpone the day of reckoning. The White House maintains that the national interest can be redefined to harmonize with the global good. It's an inspiring vision, but it contends with powerful impulses deep in our political nature.
In an era of economic distress, it is natural for our country and all countries to put blame on foreign competitors and to fear international exposure. And in the age of terrorism, it is natural for any people to insist on having every weapon available to protect themselves.
The Obama administration is asking us to transcend these basic instincts. On the economic front, it argues that a retreat from trade would deepen the recession for everyone, as it did in the 1930s. On the security front, the president says we must not use torture as a means of interrogation — even if we believe it might expose a plot or a terrorist in the short term. To do so, he says, suborns the principles the nation was founded to uphold while yielding comparatively little of value.
That view has been vigorously challenged by conservatives, chief among them former Vice President Dick Cheney, who is closely associated with the aggressive techniques. The argument is that in a brutal world, we must have all potential tools and weapons available.
As the debate goes forward, experts will disagree about the usefulness of waterboarding and other means most regard as torture (or tantamount to it). Cheney and others argue the extreme methods bore fruit, and they say classified information would prove it.
Ultimately, the Obama case rests on the idea that Americans are safest in a world where people see the United States as a beacon of principle and hope. Whatever dividends torture may yield must come at enormous cost.
Attorney General Eric Holder says the U.S. can "reclaim its standing in the world" only by making a clean break with torturous techniques. That view is popular in public opinion polls, at least in part because of the lingering unpopularity of the last administration.
But the old anger and resentment may fade with time. And the Obama White House can chart its new course toward world approval only so long as no new terrorist attack strikes the homeland. If one does, Cheney's attitude will be back with a vengeance.