George Santayana said, "Those who cannot remember the past are condemned to repeat it."
Perhaps a corollary of that axiom should be: Those who know only historical slogans should quit using them to support their causes.
For example, amateur historians remind us impatiently that the reason Iraq must disarm (which no one else is doing) is that Hussein promised to disarm at the end of the Gulf War in 1991.
Of course, they neglect to tell us that the "promise" was made at the point of a gun. You don't "freely" give your money to a mugger when he says, "Your money or your life." Promises and actions that are coerced are morally meaningless.
But citing Hussein's promise isn't the only way history is misused.
History is invoked to justify the U.S. starting a war against a foreign country (Iraq in 1991, Serbia in 1999, and now Iraq again) because "history tells us" we have to stop the latest incarnation of Adolf Hitler before he proceeds to conquer the entire world. As though Serbia or Iraq could be compared to the power of Hitler's Germany.
And the history-sloganeers remind us over and over that millions of lives would have been saved if only the Allies had stopped Hitler at Munich.
A historical slogan can be a wonderful thing. It allows you to reduce all the complexities created by billions of people to a simple equation of Good vs. Evil, white & black, us & them.