(Bernd Debusmann is a Reuters columnist. The opinions expressed are his own)

WASHINGTON (Reuters) - At the Beijing Olympics, China trounced the United States in the contest for gold medals. In the Caucasus, Russia inflicted a humiliating military defeat on Georgia, America’s closest ally in the region. At home, the U.S. economy is in deep trouble.

The misery index, a combination of the rates of inflation and unemployment, stands at its highest in 16 years (11.3 percent in July) and there are forecasts of worse to come.

The Olympics marked China’s status as a world power and the first time since 1996 that Americans did not win most gold medals. In the Caucasus, Russia showed that it can do as it sees fit in its own backyard, no matter how loudly Washington protests. That includes recognizing as independent states the two breakaway provinces, South Ossetia and Abkhazia, that Georgia claims as its own.

In the Great Power game in the region, the score so far is Russia 1, U.S. nil.

Does all this mean that the oft-predicted end of America’s role as the world’s only superpower is near? Depends on the definition of “near.”

Political power grows from the barrel of a gun, as China’s Mao Tse Tung observed, and the United States spends more on its armed forces than the rest of the world combined. There are more than 700 U.S. military bases in some 130 countries.

And despite its current troubles, the U.S. economy is larger than those of the next three countries put together.

Still, the U.S. is no longer number one in all the fields where its dominance was once taken for granted. The world’s leading financial center, for example, is no longer New York, it is London. The world’s largest investment fund is in Abu Dhabi. The world’s tallest building will soon be in Dubai.

Predictions of shrinking (or rising) American power have been wrong in the past. In his book “the Rise and Fall of Great Powers,” the Harvard historian Paul Kennedy foresaw the imminent decline of the United States. The book was published just before the Soviet Union collapsed, a turn of history that left the U.S. as the world’s only superpower.

On the opposite end of wrong forecasts was Francis Fukuyama’s famous essay “The End of History,” written after the fall of the Berlin Wall in 1989. It argued that mankind’s “ideological evolution” had ended, to be replaced by “the universalization of Western liberal democracy as the final form of human government.” Things didn’t quite turn out that way.

POST-SCRIPT TO THE END OF HISTORY

In an essay for the Washington Post this month, Fukuyama, a professor at Johns Hopkins University, conceded that “today, U.S. dominance of the world system is slipping; Russia and China offer themselves as models, showing off a combination of authoritarianism and modernization that offers a clear challenge to liberal democracy. They seem to have plenty of imitators.”

Both Russia and China are members of the world’s biggest emerging market economies, the so-called BRIC club - Brazil, Russia, India and China. They account for 40 percent of the world’s population, sit on vast foreign exchange reserves, and have geopolitical ambitions. BRIC foreign ministers had their first formal meeting in May, in the Russian city of Yekaterinburg.

Given the perils of crystal-gazing into the future shape of the world, it is not easy to find an expert willing to hazard a guess on how long American supremacy will last. But there is at least one, Nouriel Roubini, an economics professor at New York University who two years ago correctly forecast the bursting of the U.S. housing bubble and the dismal chain of events that followed. At the time, many of his fellow economists snickered.

Roubini thinks that it will take a couple of decades for “U.S. policy mistakes in economic, financial and foreign policies (to) ... erode the power of the American empire.” That would make it relatively short-lived. Depending on how you count, the Roman empire lasted more than 500 years, the British 460 or so, the Spanish around 400.

One of America’s most serious problems, Roubini writes on his website, is the fact that the U.S. is the world’s biggest net borrower and net debtor. The countries financing the American deficits are its rivals, China and Russia, and Middle Eastern oil exporters.

History, he says, provides lessons on the importance of financial prudence. “Empires ... tend to be net lenders, i.e. run current account surpluses. The decline of the British Empire started in World War II when the British fiscal deficits in the war and the current account deficits turned the empire into a net borrower and a net debtor.”

The British twin deficits were being financed by a rising power that was a net lender and a net creditor - the United States. Whether it will ever return to that state depends, in part, on the competence, or lack of it, of the next U.S. administration. President George W. Bush’s team did not set a good example.

(You can contact the author at Debusmann@Reuters.com)