Yeah it is when you are in a position of power. This is precisely how NATO has been conducting diplomacy with Yugoslavia, Libya, Syria, Afghanistan, and Iraq.
I'm just explaining to you how the real world works here. That said, Russia gave Ukraine way more chances than US gave any of the countries it invaded.
You said Russia was being diplomatic. Nobody is arguing that powerful countries are often cruel. So again, if this is Russia's diplomacy towards Ukraine, do you agree that America was diplomatic towards Afghanistan?