Which defensive operation typically involves the least amount of direct engagement?

The retrograde operation is characterized by its emphasis on withdrawal from a position in the face of enemy forces, rather than direct confrontation. This type of defensive operation seeks to preserve combat power and reposition forces to more favorable terrain or areas, allowing for a strategic retreat while maintaining a defensive posture.

In a retrograde, the goal is often to avoid unnecessary casualties and retain as much of the fighting force as possible, rather than engaging the enemy directly. The focus is on movement and repositioning rather than on holding ground through fortifications or direct combat, which differentiates it from options like area defense, where units actively engage with the enemy to protect a specific area, or fortified defense, which involves holding a position against enemy attacks.

Mobile defense, while it may involve maneuver and indirect engagement with the enemy, still operates with the intent to engage at an opportune time. In contrast, the nature of retrograde operations allows for a more strategic and less direct form of engagement, making it the operation with typically the least direct engagement.