STAFF Sergeant (SSGT) Aaron Lewis, USAF, of the 305th Security Forces, McGuire Air Force Base, New Jersey, acts as a member of the Opposing Force (OPFOR) during a MOBILITY EXERCISE (MOBEX). SSGT Lewis is advancing toward the Entry Control Point (ECP) below a simulated airfield. The MOBEX designed to test the ability of the Security Forces to establish and defend an Entry Control Point (ECP) on an air base. The evaluators of the exercise inserted various stresses against the unit, from probing patrols to frontal assault of the ECP. SSGT Lewis and the members of the OPFOR were unsuccessful in their attempt to penetrate the perimeter of the base