This chapter suggests that even with a near absence of foreign relations, in reality China was responding to the combined influence of well-understood domestic and international pressures. Chinese foreign policy during the Cultural Revolution showed what the costs were when the Party elected to run the risk of violating several of the cardinal principles of its own policy and of international systemic behavior. The chapter specifies the foreign policy origins of the Cultural Revolution under three aspects: the broadening, particularly in the mind of Mao Tse-tung, of the issue of ideological revisionism from Sino-Soviet relations to the Chinese domestic political and socioeconomic arena; the alleged delay of the Cultural Revolution necessitated by the American military intervention in Vietnam and the debate over the appropriate Chinese response; and the influence of these and other foreign policy issues on interpersonal relations among top Party leaders. All are textbook examples of the complex intermingling of foreign and domestic factors.