This policy brought King Constantine into sharp collision with one of the Central Powers, whose conceptions in regard to the Balkans had not yet been harmonized. Vienna readily acquiesced in the Greek Government's declaration that it could not permit Bulgaria to compromise {9} the Bucharest Treaty, and since by an eventual action against Bulgaria Greece would not quarrel with Austria, the Austrian Government, on its part, promised to abstain from manifesting any solidarity with Bulgaria in the event of a Graeco-Bulgarian war.[7] Not so Berlin. The German Emperor egotistically presumed to dictate the course which Greece should pursue, and on 31 July he invited King Constantine to join Germany, backing the invitation with every appeal to sentiment and interest he could think of. The memory of his father, who had been assassinated, made it impossible for Constantine to favour the Servian assassins; never would Greece have a better opportunity of emancipating herself, under the protection of the Central Powers, from the tutelage which Russia aimed at exercising over the Balkan Peninsula; if, contrary to the Kaiser's expectations, Greece took the other side, she would be exposed to a simultaneous attack from Italy, Bulgaria and Turkey, and by the same token all personal relations between him and Constantine would be broken for ever. He ended with the words: "I have spoken frankly, and I beg you to let me know your decision without delay and with the same absolute frankness." He had nothing to complain of on that score. King Constantine on 2 August replied that, while it was not the policy of Greece to take an active part in the Austro-Servian conflict, it was equally impossible for her "to make common cause with the enemies of the Serbs and to fall upon them, since they are our allies. It seems to me that the interests of Greece demand an absolute neutrality and the maintenance of the _status quo_ in the Balkans such as it has been created by the Treaty of Bucharest." He went on to add that Greece was determined, in concert with Rumania, to prevent Bulgaria from aggrandizing herself at the expense of Servia; if that happened, the balance in the Balkans would be upset and it would bring about the very Russian tutelage which the Kaiser feared. "This way of thinking," he concluded, "is shared by the whole of my people."