On came the Austrians again, only to suffer a second defeat. Then they made their third and mightiest effort, and this time every available resource of the empire was strained to the utmost; every soldier not absolutely needed elsewhere was utilized. And this time, indeed, the Austrian forces did penetrate some distance within Serbian territory, and for over a fortnight the Serbian capital was theirs. But their initial success only made their final defeat the more complete. For the third time the Serbian soldiers beat them back, and from that date, December 14, 1914, Serbia remained undisturbed by foreign invasion for almost a year.
Shortly after the beginning of the New Year, came an enemy for whom the Serbians were not so well prepared: a typhus epidemic, which took almost as many victims as had the fighting. Realizing their helplessness, the Serbians uttered an appeal for help, and almost every nation, not an enemy, including the United States, responded generously with money, and by sending Red Cross corps to nurse the plague victims. By the summer of 1915, the epidemic had spent itself, after decimating the army and the civil population.
Meanwhile a danger threatened the Serbians which overshadowed even that from the Austrians; namely the danger that other Balkan nations, and especially Bulgaria, might join the Teutonic Powers. Serbia had already shown that she could take care of the Austrians alone, but with Bulgaria attacking her flank, even the most optimistic realized that the fight against such odds probably would be hopeless.
Turkey, even while Serbia was hurling back the Austrians for the second time, in November, 1914, was the first to declare herself in favor of the Teutons by attacking the Russians. Then began the game of diplomacy to win over the Christian states to the Allies. All had declared themselves neutral, even Greece, though she was bound by a treaty to assist Serbia against foreign attack. But it was generally realized that each was only watching for the first signs of weakness on either side before deciding which to support. To give weight to her diplomacy Great Britain began her military operations on Gallipoli, on the understanding with Greece, of which Venizelos was then premier, that Greek troops should assist. But Venizelos was forced to resign by the Greek King and the governing clique, and Greece continued to maintain her neutrality.
Rumania, in spite of her leanings toward the Allies, remained firm in her neutrality. Bulgaria was more explicit; she made it understood that she would join that side which could most effectually guarantee her possession of the territory in Macedonia which she considered she had won in the First Balkan War and which was given over to Serbia and Greece after the Second Balkan War by the Treaty of Bucharest. Throughout the year the negotiations continued whereby the Allies attempted to persuade Greece and Serbia to agree to Bulgaria's terms, but Greece continued obdurate in her determination to hold all she had, and Serbia yielded only in part, and very reluctantly. In August, 1915, beginning the second year of the war, these negotiations were still in progress. As it was still unknown publicly that Bulgaria had already signed a secret alliance with Germany, the situation was considered favorable to the Allies, especially as on August 22, 1915, it was announced that Venizelos was again to become prime minister of Greece.
The first indication that King Ferdinand and his cabinet had come to a decision was in the agitation that appeared in Bulgaria itself among the leaders of the opposition parties, protesting against the Germanophile policy of the Government. On September 18, 1915, a deputation of these leaders had an interview with the king, in which they made their protest; the report was that a stormy scene occurred, in which several members of the deputation used language to the effect that should the king go against the popular feeling, which was in favor of the Entente, it would cost him his throne. They also demanded that the National Assembly be convened.
The king's reply was to order a general order of mobilization of the Bulgarian army. At the same time a note was issued to all foreign representatives in which the Government stated explicitly that Bulgaria had no intention of entering the war; that she had called her men to the colors only to maintain an "armed neutrality," as Holland and Switzerland were doing. In spite of these assurances, Greece also began mobilizing. On September 20, 1915, there appeared a significant statement in the German official report of military operations, to the effect that German artillery, stationed on the Danube opposite Semendria, had opened fire on a Serbian position. Never before had there been mention of German guns so far south. Altogether, the situation in the Balkans was now becoming acute.
On September 28, 1915, Sir Edward Grey made a statement in the British Parliament which made the world realize that a crisis in the Balkans was imminent. He announced that efforts were still being made to arrange an agreement between Bulgaria and Serbia and Greece regarding Macedonia, "but," he added significantly, "if Bulgaria assumes an aggressive attitude on the side of our enemies, we will support our friends in the Balkans with all our power, in concert with our Allies and without reserve or qualification."
This was followed up by another statement on October 1, 1915, to the effect that German and Austrian officers were arriving in the Bulgarian capital, creating a situation of "the utmost gravity." Within forty-eight hours, Russia issued an ultimatum to Bulgaria demanding that the German and Austrian officers in Sofia be removed within twenty-four hours, otherwise Russia would sever all diplomatic relations with King Ferdinand's Government. To this Bulgaria made no immediate reply, with the result that the Russian Minister left Sofia the next day. Premier Radoslavov, however, on the same day, published an official statement that there were no German or Austrian officers in Sofia and that Bulgaria had no intention of breaking her neutrality. Meanwhile came reports through Greece stating that Bulgarian troops were being massed up against the Serbian frontier. As subsequent events soon proved, Bulgaria was determined to hide her real purpose to the last moment; not until she actually made her first attack did she cease denying her hostile intentions.
That Bulgaria was acting in cooperation with the Teutonic allies was obvious, for already the Serbians had observed that great forces were being mobilized across the rivers, along her northern and northwestern frontiers, along the banks of the Danube, the Save, and the Drina.