Even if this is the case, this is not a reason to destroy millions of people more. People’s lives matter the most. Russia definitely does not kill anyone unarmed and does not torture in these territories. And Russia has stated many times that it does not want to seize the whole of Ukraine.
https://www.youtube.com/watch?v=xLfFWXUNJ_I It’s more of one playlist than a channel about quantum mechanics on Russian, but as I see it has English subtitles. A fairly clear explanation with a small amount of simple mathematics, probably the minimum that is possible. It helps to understand at least a little such a complex and illogical science for the average layman.