3-136. Infantry forces defend urban areas to defeat an attack, gain time, economize forces, protect infrastructure, protect a populace, and shape conditions for offensive or stability urban operations. Usually two or more purposes apply to urban defense tasks in urban terrain. Defensive urban operations provide leaders opportunities to turn the environment’s characteristics to the advantage of Army forces. Urban areas are ideal for the defense and enhance the combat power of defending units.
3-137. In a built-up area, the defender takes advantage of inherent cover and
concealment afforded by urban terrain. Restrictions to the attacker’s ability to maneuver and observe are taken into consideration. By using the terrain and fighting from well-prepared and mutually supporting positions, a defending force can delay, block, fix, turn, disrupt, or destroy a much larger attacking force. The defense of a built-up area is organized around key terrain features, buildings, and areas that preserves the integrity of the defense and provide the defender ease of movement. The defender organizes and plans defensive missions by considering OAKOC, fire hazards, and communications restrictions. (Refer to ATTP 3-06.11 for more information.)