This chapter examines the U.S. foreign policy process which encompasses the executive, Congress, and intelligence. It first considers American foreign policy as a primary agency of government adaptation before discussing the role of the executive as the lead agency of systemic evolution in response to foreign policy needs, taking into account the executive prerogative and judicial recognition of inherent executive power. It then describes the political and technical difficulties experienced by Congress in matching the executive in foreign policy. It also explores the ramifications of 9/11 and the war on terror for American foreign policy and concludes with an overview of U.S. foreign policy under Barack Obama.