How have conditions so changed that terms which were applicable to the ancient world--in one sense at least to the mediæval world, and in another sense still to the world of that political renaissance which gave to Great Britain its Empire--are no longer applicable in _any_ sense to the conditions of the world as we find them to-day? How has it become impossible for one nation to take by conquest the wealth of another for the benefit of the people of the conqueror? How is it that we are confronted by the absurdity (which the facts of the British Empire go to prove) of the conquering people being able to exact from conquered territory rather less than more advantage than it was able to do before the conquest took place? I am not at this stage going to pass in review all the factors that have contributed to this change, because it will suffice for the demonstration upon which I am now engaged to call attention to a phenomenon which is the outcome of all those factors and which is undeniable, and that is, the financial interdependence of the modern world. But I will forecast here what belongs more properly to a later stage of this work, and will give just a hint of the forces which are the result mainly of one great fact--the division of labor intensified by facility of communication. When the division of labor was so little developed that every homestead produced all that it needed, it mattered nothing if part of the community was cut off from the world for weeks and months at a time. All the neighbors of a village or homestead might be slain or harassed, and no inconvenience resulted. But if to-day an English county is by a general railroad strike cut off for so much as forty-eight hours from the rest of the economic organism, we know that whole sections of its population are threatened with famine. If in the time of the Danes, England could by some magic have killed all foreigners, she would presumably have been the better off. If she could do the same thing to-day, half her population would starve to death. If on one side of the frontier a community is, say, wheat-producing, and on the other coal-producing, each is dependent for its very existence, on the fact of the other being able to carry on its labor. The miner cannot in a week set to and grow a crop of wheat; the farmer must wait for his wheat to grow, and must meantime feed his family and dependents. The exchange involved here must go on, and each party have fair expectation that he will in due course be able to reap the fruits of his labor, or both must starve; and that exchange, that expectation, is merely the expression in its simplest form of commerce and credit; and the interdependence here indicated has, by the countless developments of rapid communication, reached such a condition of complexity that the interference with any given operation affects not merely the parties directly involved, but numberless others having at first sight no connection therewith.