ABSTRACT
Terrain is argued to be a better term for present purposes. Terrain and capability are related; however, it is argued that fortifications should be considered as a matter of terrain in that they are often forms of enhanced terrain or alterations to a terrain. There are instances where it becomes difficult to separate a fortress from its terrain for example, the Lines of Torres Vedras were not exactly a set of fortresses. Walls or fortresses could be regarded as fixed assets, as capability, but are better seen as aspects of terrain. It is argued that terrain on land is one kind, the sea is another. Terrain is regarded as important by theorists, including Sun-tzu, Clausewitz and Mahan. Terrain is considered quite broadly to include external aspects of other kinds as well as the various conformations of the earthly terrain where the word derives.
