I think it's pretty obvious at this point that Russia is pouring the entire future of its nation-state into keeping Eastern Ukraine and Crimea, so, I think it's probably inevitable at this point given how little international support Ukraine has by now.
Why wouldn't you need troops to stand at that border and make sure that Russia can't just regroup and invade again in 6 years? Wouldn't you call that 'Peacekeeping'?
If it turns out anything like Reddit's attempt, the false-positive rate is going to be astronomical.