What impact does defense have on the enemy's combat effectiveness?

The choice that indicates that defense increases the enemy's vulnerability aligns with the fundamental principle that effective defensive operations can force an opponent into a reactive mode rather than an offensive one. When defending, forces often concentrate on creating strong positions, utilizing terrain to their advantage, and employing tactics designed to disrupt the enemy’s plans.

This defensive posture can compel the enemy to expose themselves while attempting to penetrate these fortified positions, leading to vulnerabilities. For instance, if the defending force can anticipate and counter the enemy's moves, it can exploit gaps in their formations or create opportunities for counterattacks. This shift in the operational dynamic can create a situation where the attacking forces must confront not only the defensive measures but also the inherent challenges of their approach, making them more susceptible to losses and setbacks.

Moreover, successful defense can also affect the enemy's morale and decision-making process, as continued failure to achieve their objectives can lead to frustration and decreases in operational effectiveness. Hence, a well-executed defense plays a critical role in diminishing the enemy's combat effectiveness by increasing their vulnerability during engagements.