THIS CONCISE, penetrating book must surely be the valedictory work of the most eminent political scientist and diplomatic practitioner of our age, now in his ninety-second year. It is the summation of an extraordinarily long career spent reflecting on, and directly influencing, the course of international relations. Kissinger was born to a German-Jewish family who fled Nazi persecution in 1938, coming first to London, then the United States. His doctoral thesis was on Castlereagh and Metternich, two statesmen who, after the upheaval of the French Revolution and the Napoleonic Wars, sought to restore that equilibrium between European states posited by the Treaty of Westphalia at the end of the Thirty Years War. As National Security Adviser and Secretary of State under Presidents Nixon and