The extent of the territorial expansion that may be necessary for the settlement of the national population must not be estimated by present exigencies nor even by the magnitude of its agricultural productivity in relation to the number of the population. In the first volume of this book, under the heading "Germany's Policy of Alliances before the War," I have already explained that the geometrical dimensions of a State are of importance not only as the source of the nation's foodstuffs and raw materials, but also from the political and military standpoints. Once a people is assured of being able to maintain itself from the resources of the national territory, it must think of how this national territory can be defended. National security depends on the political strength of a State, and this strength, in its turn, depends on the military possibilities inherent in the geographical situation.