AP/Susan Walsh The lessons of history? Who needs them? Certainly not Washington's present cast of characters, a crew in flight from history, the past, or knowledge of more or less any sort. Still, just for the hell of it, let’s take a few moments to think about what some of the lessons of the last years of the previous century and the first years of this one might be for the world’s most exceptional and indispensable nation, the planet’s sole superpower, the globe’s only sheriff.