This chapter argues that Barack Obama is a modern Jeffersonian: an internationalist president, by necessity, acting with notable caution, in a world where the United States stands as the defender and promoter of electoral and economic freedoms. He is a Jeffersonian by background, inclination and belief. The 1990s were a remarkable decade for American foreign policy. Obama's immediate inheritance from his predecessor of two large, regional conflicts, amidst the context of a global War on Terrorism, have dominated his foreign policy, framing and constraining his options. American exceptionalism - the notion that America is unique and superior - is a key and widely understood feature of American foreign policy. In Syria, intervention was rendered necessary because of: the security vacuum inherited in Iraq; the evolution of the conflict to become recontextualised within discourses of chemical weapons norms and then the War on Terror; and domestic and partisan calls for action which draw on embedded notions of American exceptionalism.