(1) Pre-attack: That phase that includes all planning and testing of existing facilities, plans and Emergency Action Procedures. (2) Trans-attack period. From initial attack until civil defense personnel determine that radiation levels permit leaving shelters. Essential functions during this period would include at a minimum all FOA generated Essential War Functions (3) Post-attack period. (3.a) Immediate phase. Emphasis on recovery, would include: (3.a.a) Continuing survival activities and military operations. (3.a.b) Mobilizing military and civilian resources. (3.a.c) Restoring essential communications and transportation. (3.a.d) Increasing procurement and production of essential items. Activities related to rehabilitation, rejuvenation and restructuring from remaining resources. (USACE, Planning and Operations Guidelines, Annex V: Definitions and Common Terms, 1985, p. V-1)