1. Trench warfare was used extensively on the Western Front by both sides, after the Battle of the Marne in 1914. 2. At its core, trench warfare was a form of defensive warfare intended to halt enemy assaults and advances. 3. Trench systems were extensive and complex, intended to hinder an enemy assault while allowing for fallback positions. 4. This type of warfare was difficult and dangerous, both because of the fighting and the adverse conditions in trenches. 5.