Warfare

Defense in depth

A way of defending with a series of lightly held zones in place of one strongly held line, so that attackers lost their momentum and their artillery cover before they reached the main position, where reserves could counterattack. Germany adopted it on the Western Front in the winter of 1916–17.

Mentioned in

• Chapter V The Year of Attrition Overview
• Chapter VI The Year of Revolutions §4 Arras, Vimy and the Chemin des Dames§5 Messines and Passchendaele
• Chapter VII The Last Gamble §4 Georgette, the Marne, and Why It Failed§5 The Americans Arrive, and the Second Marne
• Chapter IX In the Trenches §1 Anatomy of a Trench System
• Chapter X The Machinery of War §6 The Learning Curve: From Lines to Combined Arms