Read this while in Vietnam or just before going!
From Wikipedia: The Quiet American is a 1955 novel by English author Graham Greene which depicts French colonialism in Vietnam being uprooted by the Americans during the 1950s. The novel implicitly questions the foundations of growing American involvement in Vietnam in the 1950s and is unique in its exploration of the subject topic through the links among its three main characters – Fowler, Pyle and Phuong. (…) The book uses Greene’s experiences as a war correspondent for The Times and Le Figaro in French Indochina 1951–1954. He was apparently inspired to write The Quiet American during October 1951 while driving back to Saigon from Ben Tre province.