Which characteristic aids in securing successful defensive operations?

Mass and concentration of combat power is a vital characteristic for securing successful defensive operations because it enables a force to deliver a potent and coordinated response to an attack. By concentrating combat power at decisive points, defenders can exploit the enemy's vulnerabilities, create shock, and disrupt their attack momentum. This approach allows for a more effective defense, maximizing the strengths of the available resources and ensuring that force is applied where it can achieve the greatest impact.

In defensive operations, it's crucial to maintain a balance between utilizing available forces effectively and managing their deployment. Massing combat power means that defenders can create overwhelming advantages in specific sectors, leveraging their capabilities to halt or repel enemy advances.

While constant communication with allies, increased firepower, and proficiency in guerrilla warfare are also important factors in overall military effectiveness, they do not directly emphasize the need to create concentrated strength essential for successful defensive operations in the same manner as mass and concentration of combat power. Such tactics can become critically decisive during engagements when the goal is not merely to survive an enemy attack but to decisively counter it.