> Lets say Russia wins, and re-integrates Ukraine.
It won't happen. If you think so then, you are not well informed about this topic. Russia has no manpower to "re-integrate" the whole Ukraine. Ukraine will always exist, but for the next years, maybe not as big as in 2014. Ukraine can still prepare itself to take the lost area back in the future. That's up to Ukraine, not to Europe.
Said that, one possibility, for now, which is part of the negotiations is Russia keep the conquered land, Ukraine joins EU/NATO. Realistically, it would be Ukraine joins EU and US won't block Ukraine applying to NATO.
> Now what does the world look like in 20 years when Russia is eye-balling Poland?
Poland, other than Ukraine, isn't one of the most corrupt countries in the World, and did their home-work. Beside it, other than Ukraine, Poland is NATO.