Ukraine and Russia are both Slavic and before the breakup of the USSR, Ukraine was just part of Russia. But after the breakup, Ukraine became a separate nation with it's own President and it's own Constitution. The Russian leaders should have understood the consequences for letting that happen. Well, now they do.
That's because my knowledge about the Russian Empire and the USSR is still kind of limited. I have studied a few of the Tsars and the October Revolution but there's still a lot missing. There's a lot more I need to study.
And yeah, I do know that Ukraine didn't even exist (except as part of the USSR) till around 1991. The ethnic Ukrainians did try to build a State several times during the October Revolution but they all fell apart and they never covered a huge part of Ukraine.
I also studied the Polish and Lithuanian interventions during the time of the Tsars. There was a lot of hostility then between ethnic Ukrainians and Russians. And yeah, the US and the EU are using that hostility for a Ukrainian land grab.
That won't end well since the US and the EU will do the same things to Ukraine that they did to Russia from 1991-1999. That should be enough to make the Ukrainians US/EU-hostile. Ukraine has stepped into a serious trap.
But Russia can't just say, "Only God knows why..." because they have to share the responsibility for what happened. They knew Ukraine was unstable and that Ukrainians didn't have any experience running a country. So they shouldn't have let it become a separate country. Maybe an autonomous region, but definitely not a country. Especially considering how Ukrainians collaborated with the Nazis during WW2.
I mean if Russia could really say that Ukraine and Russia was one nation then the US/EU couldn't have started a violent coup - or at least Russia could have intervened militarily. Russia should have understood that the West wouldn't see it as one nation.
That's why Russia didn't send any troops or military equipment to Ukraine and why Russia isn't flying warplanes over the Donbass to create a no-fly zone.
It was just a huge mistake to let Ukraine become a separate nation - with it's own President - after the USSR break-up.