The Prague Spring was a marvellous period of political liberalisation in Czechoslovakia while it was under the control of the Soviet Union after WWII. The period began on 5 January 1968, following the election of reformist Alexander Dubcek as First Secretary of the Communist Party of Czechoslovakia. It continued until 21 August 1968, when the Soviet Union invaded the country and put a stop to the liberal reforms, with the help of other members of the Warsaw Pact.
But for a few glorious months, the Czech public enjoyed relative freedom from Soviet Power. This is all pretty much thanks to Dubcek, who did not want to take Czechoslovakia out of the Warsaw Pact, but who did want to introduce a more modern style of Communism within the country. Under Dubcek’s rule, opposition parties were allowed and free elections were planned. Workers were allowed to participate in the running of their factories and there were plans to raise living standards, which is always nice. Meanwhile, travel from Czechoslovakia to other countries behind the Iron Curtain was also allowed.
The Soviet leader at the time, Leonid Brezhnev, crushed the Prague Spring because he believed its progressive policies would spread to the other Soviet satellite states and threaten the integrity of the Warsaw Pact, which he was probably right to fear. The military effort saw around 500,000 Soviet troops sent into Czechoslovakia, and Dubcek was removed from office. Despite criticism in the United Nations nothing was done as a UN resolution was vetoed by the Soviet Union.
One key thing to remember? In the aftermath of the hostile takeover, the Brezhnev Doctrine was the name given to the Soviet policy whereby the USSR would intervene in any country where socialism was seen to be under threat. As you might imagine, this heightened Cold War tensions. Why? Since the underlying aim of the Brezhnev Doctrine was to increase Soviet control of the satellite states, it resulted in a return to the Stalinist model of central control of the economy and an emphasis on the development of heavy industry at the expense of consumer goods.
The Prague Spring is also historically important because it prompted Brezhnev to focus his attentions on Afghanistan. The Soviet leader went on to invade the country in 1979 under the guise of supporting the Communist People’s Democratic Party of Afghanistan. But the real reason for the invasion was Brezhnev’s concern about the 30 million Muslims who lived inside the Soviet Union; he feared the growth of Muslim Fundamentalism and how this might lead to the breakup of the Soviet Union.
The invasion served to intensify Cold War tensions, and led to the abandonment of détente. The USSR also faced trade embargoes, and the US boycotted the 1980 Moscow Olympics as a direct result of it. On top of this, the US refused to ratify the SALT II agreement that would have led to a limited disarmament, and the Carter Doctrine saw the US prepared to go to war to protect its oil supplies from the Gulf.