From the Russian point of view, defending their long borders in the west is a complicated matter.
Particularly since most of the population lives in the plain of European Russia.
There are no real mountains in much of the country, exposing it to chilly blasts from the Arctic and not in providing a real defensible barrier to foreign invasion.
So yes, history has compelled them to act accordingly.
Over the last hundred years, Russia has been involved in x number of invasions.
What % shows them on the receiving end?