Soviet occupation of Czechoslovakia

Warsaw Pact invasion of Czechoslovakia (Operation Danube)
Part of the Prague Spring and the Cold War
Czechoslovakians carry their national flag past a burning Soviet tank in Prague.
Date 20 August 1968 – 21 August 1968 (or 17 April 1969) Location Czechoslovakia Result Warsaw Pact victory The resignation of Alexander Dubček as First Secretary of the Communist Party of Czechoslovakia (KSČ) The election of Gustáv Husák as the First Secretary of the KSČ and beginning of the Normalization era Soviet military presence in Czechoslovakia until 1991 Withdrawal of Albania from the Warsaw Pact in September 1968
Belligerents
Warsaw Pact countries:  Soviet Union Bulgaria Poland Hungary Mobilised but participation cancelled at the last moment:  East Germany	Czechoslovakia Diplomatically supported by Warsaw Pact countries: Albania Romania and by  Yugoslavia
Commanders and leaders
Leonid Brezhnev Nikolai Podgorny Andrei Grechko Alexei Kosygin Todor Zhivkov Florian Siwicki Lajos Czinege	Alexander Dubček Ludvík Svoboda Diplomatic support: Enver Hoxha Nicolae Ceaușescu Josip Broz Tito
Strength
Initial invasion: 250,000 (20 divisions) 2,000 tanks 800 aircraft Peak strength: 500,000 6,300 tanks	235,000 (18 divisions) 2,500–3,000 tanks 250 aircraft
Casualties and losses
96 killed (84 in accidents) 87 wounded 10 killed (in accidents and suicides) 4 killed (in accidents) 2 killed	108 civilians killed, 500 wounded 5 soldiers committed suicide
70,000 Czechoslovak citizens fled to the West immediately after the invasion. Total number of emigrants before Velvet revolution reached 300,000.

The Warsaw Pact invasion of Czechoslovakia, officially known as Operation Danube, was a joint invasion of Czechoslovakia by four Warsaw Pact nations – the Soviet Union, Bulgaria, Hungary and Poland – on the night of 20–21 August 1968. Approximately 250,000 Warsaw pact troops attacked Czechoslovakia that night, with Romania and Albania refusing to participate. Although East German forces were prepared to participate in the invasion as well, they were ordered from Moscow not to cross the Czechoslovak border just hours before the invasion. 108 Czechoslovakian civilians were killed and around 500 wounded in the invasion.

The invasion successfully stopped Alexander Dubček's Prague Spring liberalisation reforms and strengthened the authority of the authoritarian wing within the Communist Party of Czechoslovakia (KSČ). The foreign policy of the Soviet Union during this era was known as the Brezhnev Doctrine.

The process of de-Stalinization in Czechoslovakia had begun under Antonín Novotný in the late 1950s and early 1960s, but had progressed more slowly than in most other states of the Eastern Bloc. Following the lead of Nikita Khrushchev, Novotný proclaimed the completion of socialism, and the new constitution, accordingly, adopted the name Czechoslovak Socialist Republic. The pace of change, however, was sluggish; the rehabilitation of Stalinist-era victims, such as those convicted in the Slánský trials, may have been considered as early as 1963, but did not take place until 1967.

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