In America, England, Germany, to mention only the chief commercial countries, industries offer remunerative work to great masses of the population.  The native population cannot consume all the products of this work.  The industries depend, therefore, mainly on exportation.  Work and employment are secured so long as they find markets which gladly accept their products, since they are paid for by the foreign country.  But this foreign country is intensely interested in liberating itself from such tribute, and in producing itself all that it requires.  We find, therefore, a general endeavour to call home industries into existence, and to protect them by tariff barriers; and, on the other hand, the foreign country tries to keep the markets open to itself, to crush or cripple competing industries, and thus to retain the consumer for itself or win fresh ones.  It is an embittered struggle which rages in the market of the world.  It has already often assumed definite hostile forms in tariff wars, and the future will certainly intensify this struggle.  Great commercial countries will, on the one hand, shut their doors more closely to outsiders, and countries hitherto on the down-grade will develop home industries, which, under more favourable conditions of labour and production, will be able to supply goods cheaper than those imported from the old industrial States.  These latter will see their position in these world markets endangered, and thus it may well happen that an export country can no longer offer satisfactory conditions of life to its workers.  Such a State runs the danger not only of losing a valuable part of its population by emigration, but of also gradually falling from its supremacy in the civilized and political world through diminishing production and lessened profits.

In this respect we stand to-day at the threshold of a development.  We cannot reject the possibility that a State, under the necessity of providing remunerative work for its population, may be driven into war.  If more valuable advantages than even now is the case had been at stake in Morocco, and had our export trade been seriously menaced, Germany would hardly have conceded to France the most favourable position in the Morocco market without a struggle.  England, doubtless, would not shrink from a war to the knife, just as she fought for the ownership of the South African goldfields and diamond-mines, if any attack threatened her Indian market, the control of which is the foundation of her world sovereignty.  The knowledge, therefore, that war depends on biological laws leads to the conclusion that every attempt to exclude it from international relations must be demonstrably untenable.  But it is not only a biological law, but a moral obligation, and, as such, an indispensable factor in civilization.

The attitude which is adopted towards this idea is closely connected with the view of life generally.