When the USSR broke up and was no longer a threat, the Russian nationals were not regarded as a threat.
Now that Russia is invading their neighbors, threatening other neighbors and those same Russian nationals are going "Yay for Russia" now a threat. The same as any number of countries in the Americans suddenly found the Japanese nationals a threat when their neighbors were attacked and Japan told the world it intended to make the Pacific a Japanese lake.
You did study 20th century history in school didn't you?
Or any history?
Perhaps read a pamphlet that might have mentioned something about history?
Did massive amounts of Russian Estonians threaten the government with armed violence? No? Then you are being stupid