If a state lacks the energy and national purpose, like Italy, or the possibility, like Switzerland, for territorial expansion, and accepts its boundaries as final, the natural increase of population upon a fixed area produces an increased density, unless certain social forces counteract it.  Without these forces, the relation of men to the land would have tended to modify everywhere in the same way.  Increase in numbers would have been attended by a corresponding decrease in the amount of land at the disposal of each individual.  Those states which, like Norway and Switzerland, cannot expand and which have exploited their natural resources to the utmost, must resign themselves to the emigration of their redundant population.  But those which have remained within their own boundaries and have adopted a policy of isolation, like China, feudal Japan during its two and a half centuries of seclusion, and numerous Polynesian islands, have been forced to war with nature itself by checking the operation of the law of natural increase.  All the repulsive devices contributing to this end, whether infanticide, abortion, cannibalism, the sanctioned murder of the aged and infirm, honorable suicide, polyandry or persistent war, are the social deformities consequent upon suppressed growth.  Such artificial checks upon population are more conspicuous in natural regions with sharply defined boundaries, like islands and oases, as Malthus observed;[123] but they are visible also among savage tribes whose boundaries are fixed not by natural features but by the mutual repulsion and rivalry characterizing the stage of development, and whose limit of population is reduced by their low economic status.

[Sidenote:  Extra-territorial relations.]

There is a great difference between those states whose inhabitants subsist exclusively from the products of their own country and those which rely more or less upon other lands.  Great industrial states, like England and Germany, which derive only a portion of their food and raw material from their own territory, supply their dense populations through international trade.  Interruption of such foreign commerce is disastrous to the population at home; hence the state by a navy protects the lines of communication with those far-away lands of wheat fields and cattle ranch.  This is no purely modern development.  Athens in the time of Pericles used her navy not only to secure her political domination in the Aegean, but also her connections with the colonial wheat lands about the Euxine.

The modern state strives to render this circle of trade both large and permanent by means of commercial treaties, customs-unions, trading-posts and colonies.  Thus while society at home is multiplying its relations with its own land, the state is enabling it to multiply also its relations with the whole producing world.  While at home the nation is becoming more closely knit together through the common bond of the fatherland, in the world at large humanity is evolving a brotherhood of man by the union of each with all through the common growing bond of the earth.  Hence we cannot avoid the question:  Are we in process of evolving a social idea vaster than that underlying nationality?  Do the Socialists hint to us the geographic basis of this new development, when they describe themselves as an international political party?