In the frontispiece of his Vietnam-set novel, The Quiet American, published in 1955, Graham Greene insisted that he had written ‘a story and not a piece of history’, yet countless readers in the decades that followed ignored these cautionary words and invested the work with historical authenticity. By writing in the first person, and by including more direct reportage (drawn from his several visits to Indo-China in the 1950s) than can be found in any of his other novels, Greene underestimated the extent to which his readership would confuse fact and fiction. Greene did not intend his novel to function as history, but this is what happened. How, then, does it measure up as history? In addressing this question, most commentators have been concerned to establish the real-life inspiration for Alden Pyle, the quiet American of the book's title who is secretly (and disastrously) promoting a Third Force in Vietnam equidistant between the French colonialists and the communist-led Viet-Minh. In this article the focus is less on personalities than on whether the Americans were indeed covertly funding and arming a Third Force. In addition, using Greene's unpublished letters and diaries as well as Foreign Office documents recently released under the UK Freedom of Information Act, it will be seen that the British, too, were involved in Third Force plotting behind French backs and that Greene himself was a party to the kind of convoluted intrigue so often to be found in the plots of his novels.