I get that you’re making some weird comparison to Iraq and Afghanistan, but who besides the world itself would be the colonizer in my recommended arrangement? The world itself in my recommended United Nation governance followed by a local government chosen by their own legitimate referendums with international observers and gun free polls? Is that not better than Russia just claiming them with no say by the people (unless you believe the sham referendums under armed watch in a war zone as legitimate)?
Even if you disagree with my assessment of Russia’s annexation, isn’t an international body ( that Russia itself has membership) working with your people, with guarantees for self rule and an end to the war better than status quo?
If you’ve supported Donbas independence, with wishes for greater ties to Russia instead of Europe, you still get that in this agreement. Donbas can still legitimately join Russia in a few decades, and still trade with them now.