The American Academy of Arts and Sciences in Cambridge, Mas- sachusetts, will support seven U.S. graduate students who have been accepted in the Young Scientists' Program at the International Institute for Applied Systems Analysis (IIASA) in Vienna, Austria, during the summer of 1990. IIASA is a non-governmental, multi- lateral research organization whose research is supported by national member organizations (NMOs) from 16 countries, including the United States, Canada, Japan, the Soviet Union, and most major Eastern and Western European countries. The U.S. NMO is comprised of approximately 20 organizations and is chaired by the American Academy. IIASA's research programs deal with the behavior of large scale systems and include projects in environmental science, population and demography, and economic change. The Young Scientists' Program allows graduate students from member countries to spend a summer at IIASA, working in the ongoing research projects of permanent and visiting senior scientists. A multi- lateral IIASA committee selects Young Scientists on the basis of applications forwarded by the respective NMOs, paying particular attention to the likelihood that candidates can make substantial contributions to the research conducted at the Institute. Each NMO then seeks support for the candidates from its country who have been selected by IIASA. Current political and economic changes are having important effects on the conduct of science and engineering research in Europe and are almost certain to influence future U.S. participation in European research activities. Of particular interest are: a) the movement toward multilateral research as exemplified by European Community programs and renewed interest in existing multinational centers such as IIASA; b) the opening of Eastern Europe which is resulting in increased mobility for scientists from those countries and is facilitating access to their research sites on the part of Western investigators; and c) acknowledgment by Eastern European countries of the urgent need for research related to their severe environmental problems. In view of the rapidly changing European research context, it is important for young U.S. investigators to gain working experience in Europe early in their careers and to meet and interact with their European peers with the expectation that life-long professional bonds can ensue. NSF's support for U.S. participation in the IIASA Young Scientists' Program provides a cost-effective investment in the future, internationally-oriented careers of an outstanding group of U.S. graduate students by: a) giving them working experience in an important multilateral research organization; b) providing opportunities for interactions on a sustained basis with senior scientists and students from all over Europe; and c) involving them in critically important areas of research, such as environme- ntal science and the economic restructuring of Eastern Europe and the Soviet Union.