John F. Kennedy's loyal White House aides, Kenneth O'Donnell and Dave Powers, titled their 1972 J.F.K. memoir Johnny, We Hardly Knew Ye—despite the fact that they had served him since his days as a scrawny young congressional candidate in Boston. So it's no surprise that Americans are still trying to figure out nearly half a century after his abbreviated presidency who Jack Kennedy really was. Was he a cold war hawk, as much of the history establishment, Washington pundit class and presidential hopefuls of both parties—eager to lay claim to his mantle of muscular leadership—have insisted over the years? Or was he a man ahead of his time, a peace-minded visionary trying to untie the nuclear knot that held hostage the U.S. and the Soviet Union—and the rest of the world?

As the U.S. once again finds itself in an endless war—this time against terror, or perhaps against fear itself—the question of Kennedy's true legacy seems particularly loaded. What is the best way for America to navigate through a world where its enemies seem everywhere and nowhere at the same time? What can we learn from the way Kennedy was trying to redefine the U.S. role in the world and to invite Americans to be part of that change? Who was the real John Fitzgerald Kennedy?