Perimeter areas are widened or enhanced so as to provide
suitable protection. Examples include increased distance, improved strength
or quality in the perimeters, and the use of multiple perimeters in
combination such as the combination of a moat and a wall.
Complexity: There may be substantial cost involved in increasing or
enhancing perimeters and it may be hard to definitively determine when the
perimeter is strong enough or wide enough.
fc@red.a.net