Which game was released first, Twilight Struggle or Diplomacy? 
Twilight Struggle: Twilight Struggle: The Cold War, 1945–1989 is a card-driven strategy game for two players, with its theme taken from the Cold War. Diplomacy (game): Diplomacy is a strategic board game created by Allan B. Calhamer in 1954 and released commercially in 1959.
Twilight Struggle