Is that what you said about Crimea? Where does it stop?
There is no way to know how Russia will behave exactly, but we DO know that they stopped invading Georgia when some territory was ceded. The USA and Europe behave very differently when invading (Iraq, Afghanistan). It does not help to reduce the conflict into a bad guys/good guys story. People are dying and a whole country might get flattened to rubble.
So, more sanctions I guess. It is immoral if any EU citizen has heating this winter when that could be going to Ukraine.