Fun fact: Russia has never once invaded Central Europe. Central / West European countries have invaded Russia a few times. Russia does not need space or natural resources and it would be difficult to conquer its way to the soft factors it is missing.

Given the strength of most European countries and their lack of natural resources, the chance of a large war being a net positive for Russia is small. Of course, sometimes there are internal reasons to start a war. Falklands and some US wars and, I think, most of Russia's small wars after the cold war come to mind.