1968, Prague

In the operation, codenamed Danube, 500,000 troops (some source says even more, up to 750,000) attacked Czechoslovakia; approximately 500 Czechs and Slovaks were wounded and 108 killed in the invasion. The invasion successfully stopped the liberalization reforms and strengthened the authority of the Communist Party of Czechoslovakia (KSČ). The foreign policy of the Soviet Union during this era was known as the Brezhnev Doctrine.