G.U.A.R.D. soldiers and pilots can’t be out fighting alien horrors every hour of the day, and the defense base is a place where they can coordinate their efforts, fill out necessary paperwork, and enjoy a bit of coffee before the next battle. As these bases are often deployed in forward regions, each is heavily fortified and during emergencies can activate a bunker mode where vulnerable segments are withdrawn, during which it can sustain considerable punishment.
