No doubt the hesitation of Austria was due to the fact that, on July 28, the Russian Government warned Germany of the mobilization of the southern military districts of Russia, to be publicly proclaimed on July 29.[38] Austria replied to this intimation by offering assurances that she would respect the integrity and independence of Servia;[39] these assurances, considered inadequate by the Russian Government, seem to have been the subject of the last conversations between Russia and Austria-Hungary. Russia persisted that Germany was the real obstacle to a friendly settlement; and this conviction was not affected by the appeals for peace which the Kaiser telegraphed to the Tsar on July 28, July 29, and July 31.[40] On July 29 Germany told England that the Russian mobilization was alarming, and that France was also making military preparations;[41] at the same time Germany threatened to proclaim 'imminent state of war' (_drohende Kriegsgefahr_) as a counter measure to the French preparations;[42] German military preparations, by July 30, had in fact gone far beyond the preliminary stage which she thus indicated.[43] Germany had already warned England, France, and Russia that, if Russia mobilized, this would mean German mobilization against both France and Russia.[44] But on July 27, Russia had explained that her mobilization would in no sense be directed against Germany, and would only take place if Austrian forces crossed the Servian frontier.[45] On July 29, the day on which Russia actually mobilized the southern districts, Russia once more asked Germany to participate in the 'quadruple conference' now proposed by England, for the purpose of mediating between Austria and Servia. This proposal was declined by the German Ambassador at St. Petersburg.[46] Germany in fact believed, or professed to believe, that the Russian mobilization, though not proclaimed, was already far advanced.[47] On July 30 Austria, although her conversations with Russia were still in progress, began the bombardment of Belgrade. The next day, July 31, Russia ordered general mobilization; on August 1 France and Germany each took the like step; Germany presented an ultimatum to Russia, demanding that Russian mobilization should cease, and another ultimatum to France asking what course she would take in the event of war between Germany and Russia.