The past can never be predicted, and perhaps never more so than when it comes to the German left. Two years ago, we learned that Nobel Laureate Günter Grass -- the literary scourge of all things fascist, especially America -- had himself been a member of the Waffen SS. Now comes another zinger that casts the radical political and social upheavals of the late 1960s in new and revealing light. The historical surprise concerns a turning point whose ripple effects were felt in Europe and beyond. On June 2, 1967, a West German policeman fatally shot an unarmed, 26-year-old literature...