system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What does Putin "get" out of destabilizing Ukraine?

I can't believe that he honestly expects a unification of some or even any of the former soviet bloc countries so what end does it serve by supporting and aiding anti-Western rebels?
gpt
It prevents an organized and capable ally of EU interests (or worse, one-day NATO member) from sitting at his border; it sows discord among his foes (via disputes over sanctions, providing arms to Ukraine, etc); and it provides a warning to other former Soviet States (Georgia, Kazakhstan, and others) about what their future looks like if they try to distance themselves from Russia diplomatically/economically/militarily.