What type of operation is primarily focused on degrading the combat effectiveness of an enemy force?

The focus of the question is on operations aimed at degrading the combat effectiveness of an enemy force. An ambush is a surprise attack by combatants from a concealed position, intended to catch the enemy off guard and inflict maximum damage quickly. This operational tactic effectively diminishes the enemy's capability to respond and can significantly impact their morale and strength.

In contrast, other operations like counteroffensive operations, feints, and infiltration serve different strategic purposes. Counteroffensive operations are defensive measures intended to regain control after an enemy has gained ground. A feint is designed to deceive and divert the enemy, rather than to directly inflict damage. Infiltration involves covertly moving forces into enemy territory with specific objectives, often for reconnaissance or disruption but not primarily aimed at combat engagement. Therefore, the primary purpose of an ambush aligns closely with the goal of degrading an enemy's combat effectiveness by delivering a sudden and overwhelming blow.