way of achieving this. However, the Foreign Ministry had no solid proof of Serbian involvement and a dossier used to make its case was riddled with errors. On 23July, Austria delivered an ultimatum to Serbia, listing ten demands made intentionally unacceptable to provide an excuse for starting hostilities. Serbia ordered general mobilisation on 25July, but accepted all the terms, except for those empowering Austrian representatives to suppress "subversive elements" inside Serbia, and take part in the investigation and trial of Serbians linked to the assassination. Claiming this amounted to rejection, Austria broke off diplomatic relations and ordered partial mobilisation the next day; on 28 July, they declared war on Serbia and began shelling Belgrade. Having initiated war preparations on 25 July, Russia now ordered general mobilisation in support of Serbia on 30th. Anxious to ensure backing from the SPD political opposition by presenting Russia as the aggressor, Bethmann Hollweg delayed commencement of war preparations until 31 July. That afternoon the Russian government were handed a note requiring them to "cease all war measures against Germany and Austria-Hungary" within 12 hours. A further German demand for neutrality was refused by the French who ordered general mobilisation but delayed declaring war. The German General Staff had long assumed they faced a war on two fronts; the Schlieffen Plan envisaged using 80% of the army to defeat France in the west, then switch to Russia. Since this required them to move quickly, mobilisation orders were issued that afternoon. At a meeting on 29 July, the British cabinet had narrowly decided its obligations to Belgium under the 1839 Treaty of London did not require it to oppose a German invasion with military force. However, this was largely driven by Prime Minister Asquith's desire to maintain unity; he and his senior Cabinet ministers were already committed to support France, the Royal Navy had been mobilised and public opinion was strongly in favour of intervention. On 31 July, Britain sent notes to Germany and France, asking them to respect Belgian neutrality; France pledged to do so, Germany did not reply. Once the German ultimatum to Russia expired on the morning of 1 August, the two countries were at war. Later the same day, Wilhelm was informed by his Ambassador in London, Prince Lichnowsky, that Britain would remain neutral if France was not attacked, and might not intervene at all given the ongoing Home Rule Crisis in