Which operation involves preventing the enemy from engaging forces or assets?

The operation that involves preventing the enemy from engaging forces or assets is security operations. Security operations are designed specifically to protect friendly forces, assets, and critical areas from enemy action. This is achieved through measures like reconnaissance, establishing defensive positions, and employing various tactics to ensure that the enemy's ability to target these forces is diminished or eliminated.

In the context of military operations, security operations play a crucial role in maintaining the initiative and ensuring that forces can move freely and engage effectively. By denying the enemy opportunities to engage or counterattack, security operations create an environment in which friendly forces can operate with a reduced risk of being targeted.

While concepts such as area defense, mobile defense, and decoy defense also involve elements of protection and engagement with the enemy, they do not specifically focus on the proactive prevention of enemy actions in the same manner as security operations. Instead, they may emphasize holding territory, maneuvering to counter enemy advances, or misleading the enemy, respectively. Thus, security operations are the most aligned with the primary objective of preventing enemy engagement.