Robert Kagan, an adviser on Central American policy in the Reagan administration, offers a sharply critical history of what he perceives to be American missteps in Nicaragua during a time of revolution. A tiny and politically inconsequential country, Nicaragua occupied a front-burner place in negotiations between the United States and Soviet Union, even when neither party seemed to care much about the ultimate fate of that nation. In the end, the Reagan doctrine of containment ended in failure, as an avowedly Marxist government held power for more than a decade. But so, too, did the Soviet doctrine of expansionism yield no fruit. Kagan credits Costa Rican president Oscar Arias with finding a way to break the impasse in U.S.-Soviet-Nicaraguan relations, thanks to which the Bush administration restored full diplomatic exchange and negotiated the free elections that brought democratic forces to power in Managua.