The moment Russia mobilizes, Germany also will mobilize, and will unquestionably mobilize her whole army.
Source, in full
Remark to the Austrian Chief of Staff Conrad von Hotzndorf (21 January 1909) during the Bosnian crisis, quoted in L. C. F. Turner, 'The Significance of the Schlieffen Plan', in Paul Kennedy (ed.), The War Plans of the Great Powers, 1880-1914 (Boston: Allen & Unwin, 1985), p. 214