Russia could be sliding into dictatorship as Germany did soon after World War I, Estonian President Toomas Hendrik Ilves has warned.
"There is a mentality of being stabbed in the back that reminds me of the Weimar Republic," Mr Ilves told Russia's Moscow Times newspaper.
The Weimar Republic is the name given to the German state in 1919-1933 - before Adolf Hitler's rise to power.
Estonia-Russia ties have been tense since the collapse of the Soviet Union.
Last year, Tallinn and Moscow had an all-out row over the relocation of a Soviet-era war memorial in the Estonian capital.
"The Weimar mentality... is so similar that I really hope we do not go off in the wrong direction," Mr Ilves told the Moscow Times.
He was speaking as Russia prepares to elect a new president on Sunday. However he declined to discuss the polls.
President Vladimir Putin is stepping down after serving two terms in office and his endorsed heir, Dmitry Medvedev, is widely expected to win the 2 March elections.
None of Russia's liberal opposition parties has a candidate in the race.
One opposition leader has been barred from standing, while another has withdrawn saying the outcome is predetermined. The Russian authorities say the election will be fair.
On Tuesday, human rights pressure group Amnesty International said civil rights in President Putin's Russia were being eroded.
In a report, Amnesty said there was a systematic destruction of civil liberties and freedom of speech was "shrinking alarmingly".
The Kremlin says it is committed to human rights and accuses Western governments of using such allegations to limit Russia's global influence.