The Vietnam War became one of the most painful episodes in the history of US foreign policy, one where Kissinger himself would play a pivotal and controversial role. American leaders liked to think of themselves as selfless, concerned with the spread of democratic principles for their own sake and as willing to challenge threats to freedom anywhere in the world. This idealistic attitude turned Indochina, a French colonial possession that would later become the countries of Vietnam, Cambodia, and Laos, into a major geopolitical concern as the triumph of communism in China in 1949 made the US determined to stop its further spread. Yet Indochina remained under French control, and American idealism also required a critical stance toward overseas empire.

In response, the US sought a way to secure the independence of Indochina’s successor states while also insulating them from communism. French forces suffered a calamitous defeat against the Viet Minh insurgency in 1954 and were eager to withdraw entirely to safeguard other colonial possessions such as Algeria. Britain was also more concerned with its own colonies than Southeast Asia as such, and so John Foster Dulles reluctantly traveled to Geneva (albeit not as an official representative) to agree to the partition of Vietnam along the 17 parallel, leaving a communist government in the north and an ostensibly democratic country in the south under Ngo Dinh Diem.