Which force acts as the 'ace' in a Marine Expeditionary Unit (MEU)?

The Aviation Combat Element serves as the 'ace' in a Marine Expeditionary Unit (MEU) primarily because it provides the necessary air capabilities essential for both offensive and defensive operations. This element typically includes fixed-wing and rotary-wing aircraft, which can conduct a variety of missions, such as close air support, reconnaissance, troop transport, and casualty evacuation.

The ability to project power from the sea, enable rapid response, and provide close air support enhances the effectiveness of ground forces and contributes significantly to the overall combat capabilities of the MEU. The Aviation Combat Element's versatility and adaptability are critical in achieving mission success in dynamic environments, making it a vital asset in the MEU's ability to conduct operations.