I don't believe countries have an inherent right to defend themselves, and if I did then I would say that the DPR had the same right.

It's not the Donbas war I'm questioning, there's a reasoning chain that's understandable. Both geopolitically, strategically and culturally.

It's the full scale invasion of 2022 I'm questioning. There's no chain of thought leading to that invasion, other than greed and lust for blood by Putin and his inner circles. The nationalists were not in power by the time they began their invasion. They had already gained control of the region, Donbas, that wanted to be Russian.

There's just no way to argue the full scale invasion should ever have started.

Somehow, the extreme anti-war stance of not supporting even "defensive" wars makes me a bloodthirsty warmonger

Your endgame argument is national states shouldn't exist, but today they do. As long as they do exist, national governments should be able to defend against other nations attempt to gain control over them. Because if we do assume, at one point we get a global government and abolish the national states. Then it's whoever carries the most power (that's war machines), that'll be able to decide the values of such a government. And by extend shape the culture that'll impact everyone.