On the 20th of August 1968, troops and tanks from the Soviet Union and other members of the Warsaw pact invaded Czechoslovakia. This brought an immediate change in relations between the Soviet Union and Czechoslovakia and was due to increasing opposition to communism within Czechoslovakia, leading to reforms under Dubcek, and the reactions of Moscow to these reforms.
The first reason for a change in relations was the growth of opposition in Czechoslovakia to Soviet control. This was due to what the Soviet Union had done in 1948, they murdered Jan Masaryk. Once Jan was killed the elections were rigged and they put Antonin Novotny in power from 1957. Antonin was very unpopular amongst the Czechs as he was a hard-line communist who followed closely in the Soviet Union's footsteps and wouldn't introduce reform no matter what the Czechs wanted. He was very slow to flow Khrushchev's destalinization policy but he took much longer to release political prisoners who were jailed because of Stalin. This all caused more people to oppose the Soviet Union.
Furthermore the Soviets were concerned because: they didn't want the new ideas from Czechoslovakia to spread, Czechoslovakia was becoming closer to West Germany and industrial relations between West Germany and Czechoslovakia were improving. In 1968 on the 20-21 of August hundreds of thousands of Soviet troops along with troops from Bulgaria, East Germany, Poland and Hungary and were greeted with petrol bombs being thrown at them, as well as, buildings being set on fire, protestors assembling in Wenceslas Square, barricades being set up in streets, students tearing down street names to confuse invaders, students climbing into the tanks to try and argue with the Soviet soldiers as they were so desperate and the anti-Soviet broadcasters kept on broadcasting by moving from hiding place to hiding place but there wasn't any resistance by the Czechoslovakian army as they were ordered not to fight back and so around 100 people died, another thing that happened in 1968 was Dubcek and the other leaders being arrested and escorted to Moscow. These had consequences like the demonstrations, which continued going until April 1969, the Czech communist party being purged and the Brezhnev document - this doctrine redefined communism as a one-party system and declared that all member countries had to remain part of the Warsaw Pact
The Soviets began placing muclear missiles in Cuba in 1962 after which Fidel Castro realized that the Soviet Union was unreliable.
the two countries became less hostile toward each other
the two countries became less hostile toward each other
The two countries became less hostile toward each other.
Khrushchev inched toward more peaceful relations with the democratic west.
The USSR successfully detonates its first atomic bomb at a remote test site at Semipalatinsk in Kazakhstan code named "First Lightning ."
The soviet Union set off an atomic bomb.
the two countries became less hostile toward each other
the two countries became less hostile toward each other
the two countries became less hostile toward each other
the two countries became less hostile toward each other
the two countries became less hostile toward each other
The two countries became less hostile toward each other.
The two countries became less hostile toward each other.
The two countries became less hostile toward each other.
The Soviet Union set off an atomic bomb
Khrushchev inched toward more peaceful relations with the democratic west.
The Soviet Union set off an atomic bomb