6-32. The defense plan retains a reserve regardless of the defensive task assigned. The reserve is an uncommitted force available for commitment at the decisive moment. It provides flexibility for the commander through offensive action. The reserve is more difficult to resource in the mobile defense because so much of the available combat power is allocated to the striking force. The division or BCT tasked to provide the defensive forward security force—conducting either a cover or a guard—should not also be designated as the corps or division reserve on completion of its security operations due to the likelihood of requiring extensive reconstitution following completion of the security mission.