Strategic depth is a staple of the military literature. It refers, broadly speaking, to the distances between the front lines or battle sectors and the combatants’ industrial core areas, capital cities, heartlands, and other key centers of population or military production.

How vulnerable are these assets to a quick, preemptive attack or to a methodical offensive? Conversely, can a country withdraw into its own territory, absorb an initial thrust, and allow the subsequent offensive to culminate short of its goal and far from its source of power?

The issue is the trade-off between space and time; a classic historical case is Germany’s failure to knock out the Soviet Union in 1941–42. The Soviet retreat, in the face of the German attack, from Poland in June 1941 to the outskirts of Moscow in December 1941, allowed the Soviet Union to move its industrial base to east of the Ural mountains.

See also: military strategy