Kammala jumla mai zuwa: Bayan Yaƙin Duniya na II da kuma goyon bayan USSR-Soviet coup d'état a watan Fabrairun 1948, Czechoslovakia ya zama wani ɓangare na Soviet-led Eastern Bloc kuma yana ɗaya daga cikin mambobin kungiyar Warsaw Pact a watan Mayu 1955. A watan Agustan 1968, a cikin martani ga Prague Spring pro-democracy gyare-gyare na Czech gwamnati, da
Harin da Soviet ta jagoranta ya sake kafa mulkin kwaminisanci mai tsauri ta hanyar karfi. 108 Czech da Slovaks sun mutu kuma kimanin 500 sun ji rauni sakamakon sakamakon mamayewar. Wannan ya lalata dangantakar tsakanin kasashen biyu.