People put flowers next to the Soviet WWII victory monument in Riga
People put flowers next to a Soviet World War Two victory monument in Riga, Latvia May 9, 2020. Reuters

Russia's annexation of four Ukrainian regions on Friday brought back painful memories in the Baltic countries, which say the same playbook was used to join them to the Soviet Union in 1940.

President Vladimir Putin proclaimed Russia's annexation of Ukraine's Donetsk, Luhansk, Kherson and Zaporizhzhia regions in a speech at the Kremlin after holding what it called referendums in occupied areas of Ukraine.

Western governments and Kyiv said the votes breached international law and were coercive and non-representative.

"These events in Ukraine closely follow the scenario which was tried in the Baltics in 1940," Lithuania's Defence Minister Arvydas Anusauskas, also a historian, told Reuters.

"There is the sham self-determination, there is the festive ceremony in Kremlin, and then the annexation."

The army of the Soviet Union army entered Lithuania, Latvia and Estonia in June 1940, months after Moscow agreed with Nazi Germany to divide up this part of Europe among themselves.

The governments of the three countries were forced to resign and so-called general elections were run in July 1940 to elect communist-dominated parliaments.

A request to incorporate the countries into the Soviet Union came shortly afterwards, and was swiftly granted.

"In the scenario, what follows is terror and exploitation of local resources. Which in this case are the people, which after the annexation will be sent to die in the war," Anusauskas said.

Hundreds of thousands of people from the Baltic countries were exiled to Siberia, while many Russians came to settle, increasing the number of Russian-speakers to about a third of the population in Estonia and a quarter in Latvia.

"Of course, it happened the same way (in 1940), it is a similar story", Martins Meijers, 39, an actor, told Reuters in central Riga. "Russia as a nation did not reflect on their past, they do not admit our annexation, and they repeat the same mistakes".

In contrast to ethnic Latvians, Russian-speakers tend to believe Latvia joined the Soviet Union willingly, and that Russia - at least before the Ukraine war - was a friendly country, a pollster told Reuters.

Many countries including the United States did not recognise the Soviet annexation, but the Baltics only regained their independence in the early 1990s following years of anti-Soviet protests.

"In 1940, illegitimate Russian referendums in the Baltic states forced us into terror and occupation," Marko Mihkelson, chairman of the Estonian parliament's foreign affairs committee, tweeted last week.

"Ukraine is in a better position. They will free their lands by kicking Russia out."