wtf... What did Russia do to the Scandinavians? Why are you always afraid of Russia?
Swedish vikings were probably instrumental in founding the Russian state, and Peter the Great took much inspiration from Swedish administrative traditions when creating a new bureaucratic system, etc.
Then lately there's Crimea, Donetsk and probably Georgia. Of course it's nowhere near to what the US and some of its allies have been doing, but it's not nothing.
Still, the narrative that Finland, or even Central European countries should be worried is absurd.
We're not supposed to accuse people of being trolls, but: For someone I'm not supposed to accuse of being a troll, you sure do sound a lot like you just happen to be posting from one of Putin's troll factories.
(j/k)
How? It had never been part of Russia.
You should not wait to start being afraid when things have gone badly already. If the political problems are obvious, a more prudent approach might be more adviced.
I'm not an expert on Russia, but unstable? I can't really see that in the news cycle either. USA on the other hand have had massive riots for months and 25 000 national guard posted in the capital. The divisive politics that has accelerated with the Trump presidency where the different sides now view each others as (almost) enemies of the state, how are they going to pull themselves up from this? Seems very unstable.