The Indochina and Vietnam Wars followed one another over thirty-five years, from 1940 to 1975, yet these two closely related conflicts are usually treated separately. This book seeks to tell the story of those wars as a single historical event. Within days of France's defeat by Nazi Germany and Japan's military expansion into Southeast Asia in July 1940, the United States became involved in Indochina. Most histories quickly mention the colonial past, usually limited to the battle of Dien Bien Phu, to concentrate exclusively on the American war. A selection of published sources explains the context and the development of the long war while providing an overview of France's imprint on Indochina and Vietnam.

The question "Why were we in Vietnam?" comes up regularly regarding the root causes for the ultimate deployment of over five hundred thousand US troops, most of them conscripts, into a virtually unknown land. When France left Indochina in 1954 it became an American problem. Weeks before the murder of John F. Kennedy came the overthrow of Ngo Dinh Diem and the escalation of the war in 1965–68. Finally, Richard Nixon, after extending the war into Cambodia, enacted both the Vietnamization process and negotiations in Paris between Henry Kissinger and Le Duc Tho, until the final act in April 1975, when the US embassy rooftop with the last helicopter taking off was flashed around the world as the grand finale to the war.