Led by Alexander Dubcek, then-newly elected Communist Party leader, Czechoslovakia in the spring of 1968 initiated a process of liberalising a communist regime that had seized power 20 years earlier.
Offering more press freedom, freedom of movement and economic openness, Dubcek served up what was famously coined “socialism with a human face”.
In Moscow, the reforms were viewed as a threat to the Soviet Union’s iron grip on the eastern bloc of satellite states firmly in their control.
On the night of August 20, 1968, thousands of tanks accompanied by 200,000 Warsaw Pact soldiers from Russia, Bulgaria, Hungary, East Germany and Poland invaded Czechoslovakia.
By the next morning, scores of Czechoslovakians had been killed and the Soviets had occupied the country.
“The Prague Spring was probably the only genuine attempt of liberalisation of the Soviet-style socialism before Mikhail Gorbachev’s Perestroika,” said Matej Bily, a researcher with the Institute for the Study of Totalitarian Regimes in Prague.
“The fact that the reform process began in one of the Soviet satellites, and not in Moscow, is also very important.”
At the same time, the invasion served as a turning point for Slavic attitudes towards Russia that has endured ever since.
“Fifty years later, many Czechs are extremely suspicious about Russia and the anti-Russian moods are widespread,” said Bily.
Today, the Prague Spring stands as one of the defining moments in contemporary Czech history.
Still, while Czechs reflect on what transpired 50 years ago, many are worried their fallen oppressor may be back to haunt them as a resurgent communist political party has found its way back into the political mainstream.
After winning October’s parliamentary elections, populist billionaire Prime Minister Andrej Babis was forced to seek the approval of the Communist Party in order to establish a government after most other parties refused to back him.
The move brought the communists, who remained only in the shadows of national politics since their rule ended, back to power.
“Very important days and anniversaries like this are full of purpose and reminds us how fragile our democracy really is,” said Ivan Bartos, chairman of the upstart Czech Pirate Party.
“Andrej Babis was the one who introduced them back to power. [The communists] requested positions in state-controlled companies in exchange for their support so now you are paying with something that is not yours for political support,” he said.
“We voted against it and now we have to fight every day.”
Making matters worse, the prime minister has been dogged by a long-running dispute with Slovakia over his registration as an agent of the StB, Czechoslovakia’s communist-era police.
Earlier this year, a Slovak court rejected a demand by Babis to be cleared of his alleged cooperation with the organisation.
Delivering a speech on Tuesday to commemorate the occasion of the invasion, Babis was greeted by dozens of jeering protesters.
Blowing whistles and holding placards, demonstrators chanted “shame” as the prime minister struggled to deliver his address.
“It is very ironic and in fact it is dangerous as well. He is trying to capture even more powers in next elections pretending that he is not dangerous for democracy,” said Michal Majzner, a political activist.
“But he already has almost everything – huge fortunes, [control of the] media, intelligence, politics powers … and he has no problems to be supported by extremists.”
But Babis was not the only one to draw criticism as Czech President Milos Zeman, an ardent supporter of Russian President Vladimir Putin, refused to make a speech on what for many Czechs is the most important day in modern Czech history.
The move underscores a growing discord between traditional democratic institutions and illiberal factions looking to move away from progressive Western politics.
“We are lucky that the dissidents who wrote our constitution after 1989 were very wise and established an upper chamber of parliament. The upper chamber can effectively block any changes of constitution towards illiberal democracy,” said Majzner.
“That is our big advantage and we need to use it.”
Still, while many opponents are quick to criticise Babis and his allies for elevating the communists in 2018, other analysts warn it is dangerous to compare the situation with what occurred in 1968 while the Czech Republic today maintains a strong rule of law as well as functional democratic institutions.
“It is visible that the communists are growing their political power and have an agreement with the government, but this is not something that is the same as 1968,” said Lubomir Kopecek, a professor of political sciences at Masaryk University in Brno.