Cold War: Eight communist bloc countries, including the Soviet Union, sign a mutual defense treaty called the Warsaw Pact.

Soviet Union-dominated Warsaw Pact troops invade Czechoslovakia, crushing the Prague Spring; on the same day, Nicolae Ceauşescu, leader of Communist Romania, publicly condemns the Soviet maneuver, encouraging the Romanian population to arm itself against possible Soviet reprisals.

Albania leaves the Warsaw Pact.

The Warsaw Pact is officially dissolved at a meeting in Prague.

Former Warsaw Pact members the Czech Republic, Hungary and Poland join NATO.

Polish Minister of National Defence Radek Sikorski opens Warsaw Pact archives to historians. Maps of possible nuclear strikes against Western Europe, as well as the possible nuclear annihilation of 43 Polish cities and 2 million of its citizens by Soviet-controlled forces, are released.