But, whatever the explanation, the thunderbolt forged in 1913 was not launched till July 28, 1914, when Austria-Hungary formally declared war on Servia. The occasion was the assassination, a month earlier, of the heir to the throne, Archduke Franz Ferdinand and his wife, the Duchess of Hohenburg, in the streets of Sarajevo. The occasion, however, was not the cause of the war. The cause was that which moved the Dual Monarchy to announce a war on Servia in the summer of 1913, namely, dissatisfaction with the territorial aggrandizement of Servia as a result of the first Balkan War and alarm at the Pan-Serb agitation and propaganda which followed the Servian victories over Turkey. These motives had subsequently been much intensified by the triumph of Servia over Bulgaria in the second Balkan War. The relations of Austria-Hungary to Servia had been acutely strained since October, 1908, when the former annexed the Turkish provinces of Bosnia and Herzegovina, which under the terms of the treaty of Berlin she had been administering since 1878. The inhabitants of Bosnia and Herzegovina are Serb, and Serb also are the inhabitants of Dalmatia on the west and Croatia on the north, which the Dual Monarchy had already brought under its sceptre. The new annexation therefore seemed a fatal and a final blow to the national aspirations of the Serb race and it was bitterly resented by those who had already been gathered together and "redeemed" in the Kingdom of Servia. A second disastrous consequence of the annexation was that it left Servia hopelessly land-locked. The Serb population of Dalmatia and Herzegovina looked out on the Adriatic along a considerable section of its eastern coast, but Servia's long-cherished hope of becoming a maritime state by the annexation of the Serb provinces of Bosnia and Herzegovina was now definitively at an end. She protested, she appealed, she threatened; but with Germany behind the Dual Monarchy and Russia still weak from the effects of the war with Japan, she was quickly compelled to submit to superior force.

During the war of the Balkan Allies against Turkey Servia made one more effort to get to the Adriatic,--this time by way of Albania. She marched her forces over the mountains of that almost impassable country and reached the sea at Durazzo. But she was forced back by the European powers at the demand of Austria-Hungary, as some weeks later on the same compulsion she had to withdraw from the siege of Scutari. Then she turned toward the Aegean, and the second Balkan War gave her a new opportunity. The treaty of Bukarest and the convention with Greece assured her of an outlet to the sea at Saloniki. But this settlement proved scarcely less objectionable to Austria-Hungary than the earlier dream of Servian expansion to the Adriatic by the annexation of the Turkish provinces of Bosnia and Herzegovina.

The fact is that, if we look at the matter dispassionately and in a purely objective spirit, we shall find that there really was a hopeless incompatibility between the ideals, aims, policies, and interests of the Servians and the Serb race and those of the Austrians and Hungarians. Any aggrandizement of the Kingdom of Servia, any enlargement of its territory, any extension to the sea and especially to the Adriatic, any heightening and intensifying of the national consciousness of its people involved some danger to the Dual Monarchy. For besides the Germans who control Austria, and the Hungarians who control Hungary, the Austro-Hungarian Empire embraces many millions of Slavs, and the South Slavs are of the same family and speak practically the same language as the inhabitants of the Kingdom of Servia. And Austria and Hungary can not get to their outlets on the Adriatic--Trieste and Fiume--without passing through territory inhabited by these South Slavs.

If, therefore, Austria and Hungary were not to be left land-locked they must at all hazards prevent the absorption of their South Slav