The Serbian plot was merely the lever to set the whole machinery working, and German activities all the world over from Belgrade and Petrograd to Constantinople, Ulster, and Mexico were parts in a comprehensive piece. But while the German sword was pointed everywhere, its hilt was in Berlin. Prussia supplied the mind which conceived the policy and controlled its execution; and in the circumstances of the Prussian Government must be sought the mainspring of the war. The cause of the war was not the Serbian imbroglio nor even German rivalry with Russia, France, or Britain. These were the occasions of its outbreak and extension; but national rivalries always exist and occasions for war are never wanting. They only result in war when one of the parties to the dispute wants to break the peace; and the Prussian will-to-war was due to the domestic situation of a Prussian government which had been made by the sword and had realized before 1914 that it could not be maintained without a further use of the sword. That government was the work of Bismarck, who had been called to power in 1863 to save the Hohenzollerns from subjection to Parliament and had found in the Danish and Austrian wars of 1864 and 1866 the means of solving the constitutional issue at Berlin. The cannon of Königgratz proved more convincing than Liberal arguments; and the methods of blood and iron, by which Bismarck, Moltke, and Roon conquered Denmark, Austria, and France and annexed to Prussia the greater part of German soil, impressed upon Germany a constitution in which the rule of the sword was merely concealed behind a skilfully emasculated parliamentary system. The Reichstag with its universal suffrage was the scabbard of the Prussian sword, and it was because the sword could not do the work required of it while it lay in the scabbard that it was drawn in 1914.