In the 1983 film WarGames, tic-tac-toe is used as an allegory for nuclear war. In the climax of the film, the protagonist prevents an out of control military defense computer from launching nuclear missiles by making it repeatedly play tic-tac-toe against itself. After quickly learning that good strategy by both players produces no winner, the computer then plays through all known nuclear strike scenarios, again finding no winner. The computer concludes that "The only winning move is not to play."
