One of the very foundations of political science is the principle that geography determines destiny. In the same way that the British Isles determined the naval culture, and the frontier affected the American culture, Russia too, can be defined by its geographic characteristics.
The most obvious element of Russia's geography, is its enormous size. But the truth is that Russia's size is both an advantage as well as a liability. The very core of the Russian Federation, the Moscow region, is simply indefensible. There are no mountainous ranges, no rivers or oceans, there are no swamps or deserts. The only geographic obstacle in Russia's core is the forests and the inhospitable climate. The only thing the Russians can do in event of an invasion, is to drag out the war and bleed the enemy out. It is for this reason that Russia's history is largely about surviving invasion after invasion. These centuries long experiences left a deep mark in the Russian culture and psychology, and due to these experiences the Russian leadership became obsessed with security and survival.