Indeed, we have already come to a state of the world in which the former tradition has long ceased to correspond to actuality. So long as the means of communication remained elementary and slow, it was possible for nations to live more or less independent lives and it was in their interest to become self-sufficing and self-contained. They were sufficiently far from one another to meet only in the event of border brawls or of predatory excursions on a large scale on the part of a strong neighbour against a weaker. But with the modern development of the means of communication a policy of isolation has become utterly impossible. The world has become a neighbourhood; and national interests are inextricably intertwined. When President Wilson said in 1916 that the European War was the last great war out of participation in which it would be possible for the United States to remain, he was speaking with this particular circumstance in mind; and not even his foresight was sufficient at that time to see that the day of isolation was already over. In six months, the United States was engulfed in the bloody maelstrom. The policy of national isolation is obsolete; and the persons who advocate military preparedness and protective tariffs are “back numbers.” These atavistic policies are no longer possible except at the cost of the incalculable impoverishment of the nation which adopts them. The nation that shuts others out also shuts itself in and will slowly perish from an inbreeding mind and an ingrowing energy. For the barrier against mutual confidence and goodwill which is military preparedness, and the barrier against reciprocal trade, which is a protective tariff, hinder much more than the exchanges of friendship and trade. They hinder that exchange of spiritual, intellectual and cultural goods which are on any radical analysis more essential to a people’s growth and wealth than its trade. Even as things are, those barriers are not sufficient to prevent a certain mutuality in trade and in culture. Neither the German tariff could keep Sheffield steel out of Germany, nor does the United States tariff keep Bradford cloth out of America, and in the region of intellectual and cultural interests the commerce has attained in recent times a considerable briskness. But in the present state of the world, why should a nation still cling to the illusion that it is a source of strength to be self-contained? It is simply silly to continue to live on homemade goods and homemade ideas when one’s neighbours are ready to supply those which they are in a position to produce better than ourselves, and to supply them freely on a basis of fair exchange; and it is no compensation for the consumption of second-rate goods that it helps to increase the bank balance of a few of one’s countrymen, especially when these few countrymen who are thus profited can out of their profits procure the superior foreign article which they put out of the reach of the rest.