The USSR had been trying to get control over the Warsaw Pact since its formation, but it was not until 1968 that they were able to do so.
In january 1968, Dubcek became the leader of the communist party. He wanted to reform communism and make it more democratic
In April 1968, Dubcek brought in an Action programme Which increased investment in consumer goods and reduced central controls on what was produced.
His political reforms were extensive. other parties were allowed to share some power and censorship was Almost completely removed
Removing censorship meant people had free speech, which people used to criticise the communist party and the soviets
on the 17th of July 1968, Soviet leader Leonid Brezhnev and other leaders sent Dubcek a letter warning him of their concerns about threats to communism.
Dubcek replied that he was loyal to the Warsaw pact and agreed to bring back Censorship.
When dubcek tried to reverse his changes, there was significant demonstrations. When the police broke up the demonstrations, Strikes were organised which looked like an uprising to Brezhnev
on the 20th of August 1968, 120,000 soviet troops and 80,000 troops from Other Warsaw pact Countries invaded Czechslovakia
Petrol bombs were thrown at soviet tanks and around 100 people were killed