Able Archer 83 was a ten-day NATO command post exercise starting on November 2, 1983 that spanned Western Europe, centred on the Supreme Headquarters Allied Powers Europe (SHAPE) Headquarters situated at Casteau, north of the Belgian city of Mons. Able Archer exercises simulated a period of conflict escalation, culminating in a coordinated nuclear release. The 1983 exercise incorporated a new, unique format of coded communication, radio silences, participation by heads of government, and a simulated DEFCON 1 nuclear alert. This relatively obscure incident is considered by many historians to be the closest the world has come to nuclear war since the Cuban Missile Crisis of 1962. Some historians, including Beth A. Fischer in her book The Reagan Reversal, pin Able Archer 83 as profoundly affecting President Reagan and his turn from a policy of confrontation towards the Soviet Union to a policy of rapprochement. Read more