Abstract : This briefing seeks to answer three questions: (1) Why study the subject of tonal, government-sponsored collaboration?; (2) What did we learn from the four case studies that gave an in-depth look at the U.S. experience in sponsoring and participating in these programs?, and (3) Can these programs be evaluated and are they worth the extra effort that is required to initiate and sponsor them? This briefing is organized to answer these questions, as well as to raise points of discussion and debate among those interested in this subject. It is presented in a format that draws lessons from the case studies and then presents key questions that emerged from the cases that can serve as a guide to others seeking to formulate similar collaborative programs. The first section discusses the growing role that international collaboration is playing in science and technology (S&T). Here we also discuss the case study methodology used for this study. The second section presents a framework of lessons learned' that emerged from our examination of cases of successful collaboration. RAND created this framework as a tool to help policymakers create effective linkages in the future. The third section discusses, from the U.S. perspective, what people reported to us as some of the benefits of participating in international collaborations. The briefing has two components: a set of slides and a written accompaniment. The two parts are designed to be used together and read as a report, and it can also serve as the basis for a workshop. Agency officials seeking to explore the creation of formal international collaborations may wish to use this briefing to generate discussion and comment among colleagues and potential collaborators.