The 1990 Great Decisions program, part of an annual series on foreign policy issues, is intended to create better better public understanding through information and analyses of important international issues. Current information is presented so that participants may be stimulated toward discussion, form opinions and contribute to the policy making process. The 1990 program explores eight issues of foreign policy and international relations. The following chapters are included: (1) "U.S.S.R. and Eastern Europe: End of an Era?"; (2) "The U.S., Europe and Japan: Global Economy in Transition?"; (3) "Nicaragua and El Salvador: War or Peace in Central America?"; (4) "Vietnam, Cambodia and the U.S.: Return Engagement?"; (5) "Third World Arms Bazaar: Disaster for Sale?"; (6) "United Nations: New Life for an Aging Institution?"; (7) "Palestinian Question: Is There a Solution?"; and (8) "Global Warming and the Environment: Forecast Disaster?" Each chapter concludes with discussion questions and an annotated list of suggested readings. A key to organizations, classified by topic, lists names, addresses, and telephone numbers of organizations that can provide additional information. The results of the opinion ballot from the 1989 issue are given. Two sets of opinion ballots for 1990 topics are included, along with a general index to Great Decisions topics from 1980 through 1989. (AS)