[adorno]

Why did Russia support us in our Revolution, and in our civil war?

Completely irrelevant.

The Russia of the last 80 years bears no resemblance to the Russia of ancient history, though even then, it wasn't that friendly towards its neighbors.

Why did the Soviet Union imprison the East Germans/East Berlin, and a host of other Soviet republics?

[reasonisfaith]

Two centuries ago is not ancient.

The Russians supported the United States in its major wars because the Russian people have the same traditional values as Americans.

We still have these values, and so do the Russian people.

This is why our Great President Trump is working with Putin through backchannels to kill globalism.

And to answer your question, totalitarians tend to imprison everyone.