7-249. Control measures for an encirclement are similar to those of other offensive tasks, especially an envelopment, but with a few additional considerations. If the commander uses both an inner and an outer encircling arm, the commander must establish a boundary between them. The commander places the boundary so that each element has enough space to accomplish the mission. The inner force requires enough space to fight a defensive battle to prevent the encircled force from breaking out. The outer force requires adequate terrain and depth to its AO to defeat any attempt to relieve the encircled force.