After the political crackdown of 1968, the atmosphere had become unbearable, and the situation got worse. Because Czechoslovak science had become a strong political force during 1968, it is not surprising that the Czechoslovak Academy of Sciences figured on the list of watched institutions. A day after the occupation of Czechoslovakia by Warsaw Pact troops, the CAS was closed by order of the commanding officer. The destruction of Czechoslovak science in the 1970s has proceeded slowly but systematically, not lacking, however, a "legal" basis. and František Janouch.
On August 21, 1968, the Soviet and its Warsaw Pact allies invaded the Czechoslovak Republic, after negotiations failed, to prevent Alexander Dubcek´s Prague Spring reforms from continuing. The Soviets mustered thousands of troops from most Warsaw pact countries. The invasion was successful in stopping democratization reforms and strengthening the authority of the Communist Party of Czechoslovakia. and Jitka Vondrová.