While there may be a reason for our armchair analysts to offer an analogy of Russia defending against the Nazis or Napoleon - because that is history they still teach in American schools, more or less - the land of the Tigris and the Euphrates has its own apt history.

The Persian way of war, the way they dealt with every western invader after Alexander was to "defend in depth" (usually the scorched earth variant). Let the invader march in, extending their supply lines across the desert. Let them march to gates of Babylon, Ctesiphon, or Baghdad before offering a serious battle. And if Persia lost a battle there (and they did from time-to-time), then retreat into the highlands, drawing the invader after. And all the while, whittle away at the enemy's supply. And the Romans, mightiest military force in their world, never did conquer Persia.