It was Santayana who said that "those who refuse to learn from history are condemned to repeat it." Unfortunately, Santayana gave no guidelines as to what lesson or lessons one should be learning from any particular piece of history, and a lot of us spend a lot of time learning the wrong thing.
Case in point. In the last week or so, President Bush has apparently discovered some significant parallel or other between the situation in Iraq and the war in Korea more than fifty years ago. Most notably: South Korea borders on North Korea, which invaded in 1950 and had to be driven out by us. We've kept a major standing force in South Korea to prevent a recurrence ever since. The parallel is that Iraq borders on Iran, which might conceive a desire to invade.
Never mind that Iran has never shown any intention of invading Iraq (quite the opposite; the Iran-Iraq war of the eighties came about because Saddam Hussein conceived a desire to grab off some of Iran's oil-richer territory, an ambition he would recapitulate a couple of years later with Kuwait). Never mind that the current government of Iraq would, to all intents and purposes, be at least an ally and more likely a client of Tehran, willingly, if the U.S. were not there to prevent. Bush sees a parallel, and this is a lesson he has learned from history.
Or is it simply an excuse? For several years now the Bush administration has insisted that it has no intention of maintaining an American presence in Iraq sine die — this despite the fact that the new American embassy being built in Baghdad would put Nero's Golden House to shame. But it now appears that the administration, despite its insistence, has been building towards at least four major permanent military bases in Iraq. Why have a permanent military presence if not to prevent Iraq from invasion? And therefore the parallel with Korea looks, from an ideological point of view, like a good one — permanent military bases in Korea have kept the north from launching another invasion, why can't permanent military bases in Iraq have the same effect on Iran?
(There's another point, as well. The South Koreans, for the most part — not all! — were perfectly happy to have our troops in their country, for precisely the stated reason. The people of Iraq have demonstrated less enthusiasm for the continued presence of U.S. troops; no more than 1% want a continuing U.S. presence in their country, and approximately three quarters have indicated that they would be happy to see the United States leave yesterday.)
Another possible parallel, of course, is with the Vietnam War. One can argue that "failure" (whatever that would be, different from our current policy) in Iraq would lead to the deterioration of democracy throughout the entire Middle East. This is a parallel to the theory of the "domino effect," which dominated much of strategic thought during the Vietnam War; namely, in its most extreme form, that should South Vietnam fall, all of southeast Asia would quickly follow suit. Of course, this didn't happen. Laos was already under North Vietnamese domination before the fall of Saigon; the only immediate result outside of South Vietnam was the fall of Cambodia to the Khmer Rouge, and even that was temporary — it was a Vietnamese army that, three years later, marched into Phnom Penh and replaced the Pol Pot government with the far less draconian one of Heng Samrin (and later Cambodia was restored to what we amusingly refer to as "the international community"). No other countries suffered any change of political direction.
So it appears that those who do not refuse to learn from history will nevertheless not learn real lessons, but will learn pretty much what their beliefs tell them to learn. And so they, too, are likely to repeat history — just not the history they think they're repeating.