Strategic depth is a term in military literature that broadly refers 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. The key precepts any military commander must consider when dealing with strategic depth are how vulnerable these assets are to a quick, preemptive attack or to a methodical offensive and whether a country can 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.
Commanders must be able to plan for both eventualities, and have measures and resources in place on both tactical and strategic levels to counter any and all stages of a minor or major enemy attack. These measures do not need to be limited to purely military assets, either—the ability to reinforce civilian infrastructure or make it flexible enough to withstand or evade assault is very valuable in times of war. The issue was the trade-off between space and time as witnessed by Germany’s failure to defeat the Soviet Union in 1942. In the face of a German invasion, the Soviet military retreating from occupied Poland in June 1941 to the outskirts of Moscow in December 1941 allowed the Soviet Union to move its industrial base to the east of the Ural Mountains. Thus the industries that had been moved could build the resources needed for the Soviet counter-attack.
Strategic depth Wikipedia
Israel is a narrow country, and its internationally recognized borders leave it just 85 miles (137 km) across at its widest point and 9 miles (14 km) at its narrowest (between Tulkarm and Tel Aviv). A number of Israeli leaders (originally Abba Eban) have referred to Israel's internationally recognized borders (those the country had from 1948 to 1967) as the "Auschwitz borders" because of the perceived danger of annihilation by regional foes. Since 1967, Israel has occupied the West Bank, somewhat widening the area under the military's effective control.
To compensate for the lack of strategic depth, Israel approaches all wars as "must-win." This puts a great importance on deterrence (partially by threat of nuclear weapons), superior firepower, and the use of pre-emptive war to prevent threats from encroaching on Israeli territory. Yitzhak Rabin said about the Six-Day War (considered a classic example of pre-emption):
The basic philosophy of Israel was not to initiate war, unless an active war was carried out against us. We then lived within the lines prior to the Six-Day War, lines that gave no depth to Israel—and therefore, Israel was in a need, whenever there would be a war, to go immediately on the offensive—to carry the war to the enemy's land.
Israeli leaders consider the issue of strategic depth to be important in negotiating its final borders as part of the Israeli–Palestinian peace process. Issues of contention include the West Bank settlements and potential Israeli control of the Jordan Rift Valley after the creation of a Palestinian state.