In Spheres of Intervention, James R. Stocker examines the history of diplomatic relations between the United States and Lebanon during a transformational period for Lebanon and a time of dynamic changes in US policy toward the Middle East. Drawing on tens of thousands of pages of declassified materials from US archives and a variety of Arabic and other non-English sources, Stocker provides a new interpretation of Lebanon's slide into civil war, as well as insight into the strategy behind US diplomatic initiatives toward the Arab-Israeli conflict. During this period, Stocker argues, Lebanon was often a pawn in the games of larger powers. The stability of Lebanon was an aim of US policy at a time when Israel's borders with Egypt and Jordan were in active contention.

Following the June 1967 Arab-Israeli War, the internal political situation in Lebanon became increasingly unstable due to the regional military and political stalemate, the radicalization of the country's domestic politics, and the appearance of Palestinian militias on Lebanese territory. US officials were more deeply involved in Lebanese affairs than most outside the region realized. After a series of internal crises in 1969, 1970, and 1973, civil war broke out in Lebanon in 1975. The conflict reached a temporary halt after a Syrian military intervention the following year, but this was only an end to the first stage of what would be a sixteen-year civil war. During these crises, the US sought to help the Lebanese government in a variety of ways, including providing military aid to the Lebanese military, convincing Arab countries to take measures to help the Lebanese government, mediating Lebanon's relations with Israel, and even supporting certain militias.