One of the first things I learned about the ancient Olympic games was that a truce was declared throughout the Greek world when the games occurred. Later, I learned that this wasn't necessarily accurate. Nevertheless, since the games were a sacred festival dedicated to Zeus, they weren't interrupted in wartime. Athletes had safe conduct to reach Olympia for the games; to deny them meant offending the god.
Whatever the truth of the ancient world, the modern Olympics have been regarded as festivals of peace. As such, they've been closed down during wartime, in 1916, 1940 and 1944. Safe conducts for athletes and spectators were more difficult to arrange in the 20th century, apparently. What's certain is that the International Olympic Committee doesn't have the power of Zeus with which to threaten recalcitrant nations.
Since World War II, the greater danger has been the corruption of the modern Olympic ideal by international politics rather than war. We've seen African nations boycott the games as long as the apartheid regime of South Africa was allowed to attend. The United States boycotted the Moscow games of 1980 to protest the Soviet invasion of Afghanistan. The USSR and Warsaw Pact boycotted the Los Angeles games of 1984 in a petty tit-for-tat gesture.
Now the partisans of Tibetan independence would have nations boycott the Beijing games of 2008 to protest Chinese rule over the land of the lamas. Others want a boycott to protest Chinese tyranny in general. Tibetan sympathizers disrupted the torch-lighting ceremony at Olympia today, no doubt to the applause of "freedom-loving" people worldwide. I'd applaud a successful Tibetan uprising against China, but I can't condone any effort to disrupt the games for their sake.
Ever since the Berlin games of 1936, freedom-loving people have had the idea that hosting the Olympics "confers legitimacy" on the host nation. When they decide that the host is illegitimate, as was Nazi Germany, the USSR, the People's Republic (and the USA?), they demand that the Olympic ideal take a backseat to ideological partisanship, lest the games "confer legitimacy" on tyrants. This is the same mentality that requires an American president not to meet with "anti-American" leaders lest they "confer legitimacy" on rogue states and evil men. In both cases, the subtext is that freedom-loving people, represented by athletes or presidents, have the right to confer or refuse legitimacy to obnoxious nations. They even project their fantasy onto the hated leaders, asserting that China bid to host the games in order to win legitimacy for themselves.
Let's get over this notion that another government's legitimacy is a matter of our opinion. While we're at it, let's stop using the Olympics as a political tool. Even if we concede the corruption of the modern amateur ideal due to drug enhancement, government subsidies, etc., we should still uphold the Olympics as a cosmopolitan occasion that brings people of all nations together in non-violent competition dedicated to furthering human ability. That ideal ought to transcend all geopolitical and ideological prejudices. For a couple of weeks every four years, at least, the world ought to rise above all that garbage. Let's not assume that everyone who attends the Olympics or watches on television endorses the occupation of Tibet or the Communist party's monopoly on power or the repression of the Falun Gong cult. Let the games go on, and then the struggle can go on.