People don't realize how much this situation could destabilize the rest of Eastern Europe. Don't forget that World War II essentially began when the West "gave" Hitler his first conquest.
That is what Putin is, another wannabe Hitler or Stalin. Anyone who doesn't see this is incredibly ignorant. What would keep Putin from wanting to add other Eastern countries.
There is no way to equate Syria with this. That is an internal situation. No country is invading another country.
The Russians are a huge threat and need to be dealt with. Americans don't understand this because we have never lived in an occupied country. My parents lived under communism.