This weekend, President George Bush kicked off an important swing through Europe and the Middle East with an emotional and deliberately symbolic tour of the Auschwitz and Birkenau concentration camps.

"The sites are a sobering reminder...of the power of evil and the need for people to resist evil," a somber Bush told reporters, minutes after writing "never forget" in a memorial guestbook. "This site is a sobering reminder that when we find anti-Semitism, whether it be in Europe or anywhere else, mankind must come together to fight such dark impulses... May we always remember."

Remembering the appeasement of Adolf Hitler—especially the September 1938 Munich Agreement, when British Prime Minister Neville Chamberlain and French Premier Edouard Daladier handed western Czechoslovakia to the belligerent Nazi dictator—has been a cornerstone of American foreign policy since World War II. And successive American presidents have been moved by the legacy of the Holocaust to the point of redirecting their foreign policy.

"Munich i.e., the consequences of appeasing fascist aggression in the 1930s was invoked in the late 1940s on behalf of establishing the containment of Soviet power and influence as the organizing principle of American foreign policy," former Armed Services Committee staffer Jeffrey Record wrote in a March 1998 Air War College paper entitled Perils of Reasoning by Historical Analogy: Munich, Vietnam, and American Use of Force Since 1945. "It was subsequently invoked on behalf of the Truman administration's decision to fight in Korea; on behalf of containment's militarization and extension to Asia and the Middle East; and on behalf of the Johnson administration's decision to intervene in the Vietnam War."

John F. Kennedy wrote his senior honors thesis on "Appeasement at Munich," and invoked the lessons learned during the Cuban Missile Crisis. The first President Bush, whenever he was on the verge of going wobbly about expelling Saddam Hussein from Kuwait, relocated his spine by reading books like Martin Gilbert's The Second World War: A Complete History. "Nothing like this since World War II," he told interviewer David Frost on Dec. 16, 1990, as recounted in Bob Woodward's The Commanders. "Nothing of this moral importance since World War II."

Bill Clinton started as a Vietman Syndrome president, but ended as a notable Munichite. The turning point was the April 1993 opening of the Holocaust Museum in Washington, D.C., when dissidents-turned-politicians Vaclav Havel, Lech Walesa and Hungary's Arpad Goncz each lobbied the president to expand NATO, and consider intervening in Yugoslavia.

Later, Clinton described that meeting as "the clearest example I know...that NATO is not dead," according to Ronald Asmus' Opening NATO's Door. His conversion gathered steam when Carterite Secretary of State Warren Christopher was replaced by the Czech-born Madeleine Albright, who made a point of telling reporters that "Munich is my mindset." Chamberlain's appeasement thus made a comeback during American interventions in Bosnia and Kosovo.

More recently, the appeasement card (or, in the words of novelist/blogger Roger Simon, the "Auschwitz Factor"), has been played by Gulf War II advocates in response to critics wondering where all the vaunted weapons of mass destruction are.

When asked about the WMD issue during a pre-trip briefing, National Security Advisor Condoleeza Rice said: "Let's not lose sight of the mass graves that are being found there, that are testament to what this regime was like."

Bush echoed this reasoning in his major European speech, delivered in Krakow.

"For my country, the events of September the 11th were as decisive as the attack on Pearl Harbor and the treachery of another September in 1939," he said. "And the lesson of all those events is the same: aggression and evil intent must not be ignored or appeased; they must be opposed early and decisively."

But does the comparison hold up, and lead to good policy? For Jeffrey Record, the ghost of Chamberlain had its uses in forming the post-war world and containing the Soviet Union, but fell apart when crossing the Pacific. "Reasoning by historical analogy can be dangerous, especially if such reasoning is untempered by recognition that no two historical events are identical and that the future is more than a linear extension of the past," he wrote. "In Vietnam...Munich blinded rather than enlightened American policy-makers....[And] helped lay the foundation for the very disaster, memories of which today shape U.S. policy just as profoundly as did Munich in Southeast Asia."

There is a nearly impossible-to-find line between learning lessons from historical events and fighting the last war. The disaster of Munich was begat by the "lessons of Versailles"—which at the time included: Don't saddle a vanquished enemy with overly onerous reparations, and maybe these new post-empire nation-states weren't such a good idea after all (a chauvinism which greatly influenced the West's indifference to Czechoslovakia's being overrun in March 1939). The greatest lesson of World War I, for many people, was the simple truth that War is Hell and to be avoided at all costs (including appeasement).

Further, the necessity to "confront evil at its source," often requires allowing that goal to supersede all others, which usually involves teaming up with bedfellows who can be objectively described as pretty damned evil themselves. The lessons of Munich, bracing as they are, led to the lessons of Yalta, when an evil Soviet ally was appeased with a sphere of influence that stifled hundreds of millions.

The Munich Agreement was a last-ditch effort to avoid world war with a dictator already known to be murderous, anti-Semitic and expansionist. It is always worth remembering that his subsequent conquering of Poland, France, the Low Countries and elsewhere were not enough to convince the U.S. to confront what was by then one of the most obvious manifestations of evil in history.

Fighting dictators who are evil mostly to their own subjects is just a fundamentally different question. One worth asking every day, and one that shouldn't be side-stepped with the excuse "yeah, but it's complicated!"...But one that doesn't lend itself to an easy answer.