Able Archer 83 participant North Atlantic Treaty Organization
The exercise scenario began with Orange (the hypothetical opponent) opening hostilities in all regions of ACE on 4 November (three days before the start of the exercise) and Blue (NATO) declaring a general alert. Orange initiated the use of chemical weapons on 6 November and by the end of that day had used such weapons throughout ACE. All of these events had taken place prior to the start of the exercise and were simply part of the written scenario. There had thus been three days of fighting and a deteriorating situation prior to the start of the exercise. This was desired because—as previously stated—the purpose of the exercise was to test procedures for transitioning from conventional to nuclear operations. As a result of Orange advance, its persistent use of chemical weapons, and its clear intentions to rapidly commit second echelon forces, SACEUR requested political guidance on the use of nuclear weapons early on Day 1 of the exercise (7 November 1983).
Thus, on November 7, 1983, as Soviet intelligence services were attempting to detect the early signs of a nuclear attack, NATO began to simulate one. The exercise, codenamed Able Archer, involved numerous NATO allies and simulated NATO's Command, Control, and Communications (C³) procedures during a nuclear war. Some Soviet leaders, because of the preceding world events and the exercise's particularly realistic nature, feared that the exercise was a cover for an actual attack. A KGB telegram of February 17 described one likely scenario: