> Ignoring everything after the war started because we are talking about how it started, it seems to me that everything you mentioned is related to the NATO issue, isn't it?

No, I don't think so. Russia intervened in Belarus to keep Lukashenka (sp) in power, against the will of the people. I don't think the people were asking for Belarus to join NATO, though. So I think that Russia has more "red lines" than NATO. A color revolution and/or a real democracy anywhere in the former USSR is a red line, at least while Putin is in power. (Because Putin very deeply fears a color revolution in Russia.)

And I think that's the deeper point. These aren't Russia's red lines; they're Putin's. And Putin may develop other things that become "red lines", because the bottom line is "anything that Putin feels threatened by". That's not a reasonable expectation to place on other nations. Ukraine and Belarus are not Putin's playthings, nor his colonies. "Don't do anything Putin doesn't like" is not something that independent nations have to play along with.