6-124. Ultimately, the mission of BCTs located within the MBA is to defeat the enemy attack or to destroy the attacking enemy force. These BCTs perform many different tasks—defending, delaying, attacking, or performing in an economy of force role—to accomplish this mission. BCTs plan to conduct forward and rearward passages of lines. They normally plan to avoid being bypassed by enemy forces during combat operations unless it fits within the corps or division commander’s intent.