In order to understand properly the underlying causes which were responsible for the outbreak of the Great European War of 1914, it is necessary to be acquainted with the recent historical development of the various nations involved. In considering the various phases of this development it becomes evident that in modern times the history of any one country exerts a powerful influence upon the history of all the other countries. The vast development of means of communication between the various countries of the earth—railways, steamships, telegraphs, telephones—resulted in an equally vast increase of their commercial and social intercourse until one might almost claim that there is not a single event of any importance whatsoever happening in one country which does not make its influence felt throughout the entire world. It is not always easy or even possible to determine the exact degree to which the various nations of the world are affected by this mutual interdependency, and frequently many years elapse before it becomes evident at all that what one nation has done or neglected to do has an important relation to the fate of another nation, even though the two nations may have few points of contact and be separated by great distances. To describe historical events as they happen day by day or even year by year throughout the modern world is an almost hopeless task, because a description of this nature would result in a confusion which would be even worse than an entire lack of knowledge concerning these matters. We will, therefore, consider separately the historical development of each nation and thereby try to arrive finally at a clear understanding of the historical causes of the Great War of 1914. Some of these causes, of course, may be claimed to go back to the beginnings of the history of the various nations; but a majority of them had their origin in comparatively recent times. It is also true that the Napoleonic Wars resulted in certain international alignments some of which, at least in part, held over until comparatively recently. But it was only approximately at the beginning of the second half of the nineteenth century that international relations assumed the important position and the fateful influence which they hold now. The short war of 1866 between Prussia and Austria, fought primarily to determine the supremacy in German affairs, may conveniently be considered for our purposes a starting point of modern international history because it resulted in changes so important that their final results had a powerful influence over the fate of the entire civilized world. Inasmuch as this war affected more directly Germany and Austria, we will first consider these two countries.