On what date did Britain declare war on Germany following an " unsatisfactory reply " to the British ultimatum that Belgium must be kept neutral ?
On July 11 , Tschirschky reported to the German Foreign Minister von Jagow that he “ again took the occasion to discuss with Berchtold what action was to be taken against Serbia , chiefly in order to assure the minister once again , emphatically that speedy action was called for . ” On the same day , the German Foreign Office wanted to know if they should send a telegram congratulating King Peter of Serbia on his birthday .