Role of United States in the Vietnam War. Operation Rolling Thunder, Battle of Khe Sanh, Tet Offensive, My Lai Massacre, Operation Menu, Cambodian Campaign, Operation Lam Son 719, Operation Linebacker II, Military Assistance Command, Vietnam - Studies and Observations Group, United States Air Force In South Vietnam, Opposition to the US involvement in the Vietnam War, History of Vietnam, Vietnam War, Military history of the United States