Born Lev Davidovich Bronstein in southern Ukraine, Trotsky was both a world-class intellectual and a man capable of the most narrow-minded ideological dogmatism. He was an effective military strategist and an adept diplomat, who staked the fate of the Bolshevik revolution on the meager foundation of a Europe-wide Communist upheaval. He was a master politician who played his cards badly in the momentous struggle for power against Stalin in the 1920s. And he was an assimilated, indifferent Jew who was among the first to foresee that Hitler's triumph would mean disaster for his fellow European...