The article reconstructs the history of the unique Middle East Regional Cooperation Program (MERC) international aid program, initiated by U.S. authorities shortly after the Camp David Accords between Israel and Egypt that U.S. diplomats helped negotiate. This program, which was designed to promote regional peace through financing research collaboration between Israeli and Arab scholars, has been going on uninterruptedly for almost half a century. However, Russian scholars in both American and Middle Eastern Studies have never substantively examined the MERC Program, the few foreign authors interested in this initiative have limited themselves to reviewing its implementation in the 20th century. This article aims to fill this gap in the historiography of U.S. mediation in the Middle East by drawing on a set of sources that cover the period of eight U.S. presidents (from J. Carter to J. Biden), many of which are being introduced into scholarly circulation for the first time. Exploration of the origins of the MERC Program and the U.S. Congress documents allowed to identify the crucial role of the U.S. legislators in its launch and support during the last decade of the Cold War. An analysis of independent reports on the implementation of the program and the testimonies of American, Israeli and Arab scholars helped reveal the differences in assessments of the initiative and the contribution of “triangular” projects to the improvement of the regional climate. It was found that the 1991 Madrid Conference and the launch of the Oslo peace process in 1993 gave a new impetus to the development of the MERC Program. The improvement in the external situation led to the U.S. transition from the original mediation model to funding direct contacts between Israeli and Arab scholars, an emphasis on the involvement of Palestinians, and an increase in the number of projects and participants. However, the importance of the MERC Program has steadily declined throughout the 21st century. This resulted both from a shift in priorities due to the Global War on Terrorism and from the almost complete halt in the Palestinian-Israeli peace process, which none of the last four U.S. administrations has been able to relaunch successfully.