The "Bucharest Nine" group of nations formed for exactly this reason. They are the group of ex-Soviet states along Russia's border that most want to see Russia defeated if not outright destroyed.

They are also the countries that allied with Germany against Russia in WWII. Suffice it to say there is still enough bad blood there to start another conflict.

And two of the B9 countries - Poland and Romania - have missile batteries that can hit Moscow in just a few minutes.