Viviani, then Premier of France, in an address before the French Chamber of Deputies, said:
The Balkan question was raised at the outset of the war, even before it came to the attention of the world. The Bucharest Treaty had left in Bulgaria profound heartburnings. Neither King nor people were resigned to the loss of the fruits of their efforts and sacrifices, and to the consequences of the unjustifiable war they had waged upon their former allies. From the first day, the Allied governments took into account the dangers of such a situation, and sought a means to remedy it. Their policy has proceeded in a spirit of justice and generosity which has characterized the attitude of Great Britain, Russia and Italy as well as France. We have attempted to re-establish the union of the Baltic peoples, and in accord with them seek the realization of their principal national aspirations. The equilibrium thus obtained by mutual sacrifices really made by each would have been the best guarantee of future peace. Despite constant efforts in which Roumania, Greece and Serbia lent their assistance, we have been unable to obtain the sincere collaboration of the Bulgarian Government. The difficulties respecting the negotiations were always at Sofia.
At the beginning of the war it appears, therefore, that Bulgaria was entering into negotiations with the Allies, hoping to regain in this way, some of the territory she had lost in the Second Baltic War. Many of her leading statesmen and most distinguished generals favored the cause of Russia, but in May came the great German advance in Galicia, and the Allies' stalemate in the Dardanelles, and the king, and his supporters, found the way clear for a movement in favor of Germany. Still protesting neutrality they signed a secret treaty with Berlin, Vienna and Constantinople on July 17th. The Central Powers had promised them not only what they had been asking, in Macedonia, but also the Greek territory of Epirus. This treaty was concealed from those Bulgarian leaders who still held to Russia, and on the 5th of October Bulgaria formally entered into war on the side of Germany, and began an attack on Serbia.
The full account of the intrigue which led to this action has never been told. It is not improbable that King Ferdinand himself never had any other idea than to act as he did, but he dissembled for a long time. He set forth his claims in detail to the Allies, who used every effort to induce Roumania, Greece and Serbia to make the concessions that would be necessary. Such concessions were made, but not until it was too late. In a telegram from Milan dated September 24th, an account is given of an interview between Czar Ferdinand and a committee from those Bulgarians who were opposed to the King's policy.