Soviet hardliners sought to seize the state to block the New Union Treaty, but the army's sudden refusal to fire on the Russian White House broke the coup in three days.
Over a million East Germans were curbed by Soviet forces during a brief window when the US 7th Army and NATO headquarters stood on alert to prevent a global catastrophe.
Pro-Soviet loyalists were purged and 600 executed without trial before Amin's secret meetings with American officials convinced the Kremlin that their ally had become a security breach.
Soviet sailors and rocket technicians were forbidden from going home and primed to deliver a "crippling blow" to the U.S. during the 1962 Caribbean confrontation.
84 people were killed or wounded and 700 arrested as Soviet divisions occupied East German cities to stop what Moscow called a foreign operation by fascist-like elements.