A timely, informed plea from New York's senior US senator ``to make the world safe for and from ethnicity.'' Moynihan presented an early version of this material in November 1991 as a lecture at Oxford; he's updated that text with notes on such events as the ``ethnic cleansing'' occurring in Bosnia. There's a certain amount of self-congratulation here (guess which politician, virtually alone in the 80's, predicted the collapse of the Soviet Union while the ``realists'' wailed about the Red tide?), but, at his best, Moynihan displays erudition and a mastery of material. Both the American liberal belief in a melting pot and the Marxist belief in class solidarity, he shows, badly underestimated ``the persistence of ethnicity.'' Although a believer in Woodrow Wilson's notion of international law, he points out what a Pandora's box that visionary's concept of ``self- determination'' has proven. Not only did Wilson refuse to apply the concept to America's allies (notably regarding Britain's control of Ireland), but he was ignorant of the idea's presumed beneficiaries and fuzzy about what the term meant in the first place. Moynihan lucidly explains how Communists pushed self-determination for ethnic groups without reconciling this with an international proletarian movement; how the UN Charter has been bedeviled by contradictory clauses on self-determination and noninterference with nations' internal affairs; and how preferential policies for majorities and entrenched minorities, both abroad and at home, exacerbate intergroup conflict. Throughout, the senator's mordant observations on historical myopia are leavened with typically puckish wit (``For years Europeans asked: Why is there no Socialist movement in the United States? The answer may be that we knew better''). The latest in a series (On the Law of Nations, 1990, etc.) demonstrating that Moynihan may be America's foremost literary politician--someone who can advance policy as cogently on the written page as on the stump.