But late on July 31st, a so-called "conversation" took place at Vienna between Count Berchtold and the Russian Ambassador, and as a result, the Austrian Ambassador at St. Petersburg was instructed to "converse" with the Russian Minister for Foreign Affairs. This important concession of Austria was conveyed to Sazonof by the Austrian Ambassador at St. Petersburg, who expressed the readiness of his Government to discuss the substance of the Austrian ultimatum to Servia. M. Sazonof replied by expressing his satisfaction and said it was desirable that the discussions should take place in London with the participation of the Great Powers. M. Sazonof hoped that the British Government would assume the direction of these discussions. The whole of Europe would be thankful to them. It would be very important that Austria should meanwhile put a stop provisionally to her military action on Servian territory.[77] [Footnote 77: English _White Paper_, No. 133.] _It is important to note that Austria's change of heart preceded by some hours the Kaiser's ultimatum to Russia._ The former took place some time during the day on July 31st. The latter was sent to St. Petersburg on the midnight of that day. It must also be noted that while Austria thus agreed at the eleventh hour to "discuss the substance of the ultimatum," it did not offer to suspend military preparations or operations and this obviously deprived the concession of its chief value.[78] [Footnote 78: _See_ Addendum, p. 191-2.] The cause and purpose of Austria's partial reversal of its policy at present writing can be only a matter of conjecture. When Austria publishes its correspondence with Germany, we may know the truth. Two theories are equally plausible: Austria may have taken alarm at the steadfast purpose of Russia to champion the cause of Servia with the sword. If so, its qualified reversal of its bellicose attitude may have induced the war party at Berlin to precipitate the war by the ultimatum to Russia. In that event, Germany's mad policy of war at any cost is even more iniquitous.[79] [Footnote 79: _See_ Addendum, p. 190, _et seq._] The supposition is equally plausible that Austria had been advised from Berlin that that night Germany would end all efforts to preserve the peace of Europe by an ultimatum to Russia, which would make war inevitable. The case of Germany and Austria at the bar of the world would be made morally stronger if, at the outbreak of hostilities, the attitude of Austria had become more conciliatory. This would make more plausible their contention that the mobilization of Russia and not Austria's flat rejection of all peace overtures had precipitated the conflict.