Perhaps denying participation at the olympic games to countries at war would make politicians think twice and help form public opinion. Would that be so bad? I take it you would not like it if the USA was refused entry and perhaps ask why? Perhaps you would even raise a stink about it when your athletes had their dreams broken? I know I would if Norway was refused entry.
Looking into the history of the games, this was one of the ideas behind at least the modern games.

We can discuss the foreign and domestic policy of the USA, but that was not the point. I mentioned Russia and Georgia as they are both part of Europe.

Certainly potential for another thread here.