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 9th , Berchtold advised Franz Joseph I of Austria that he would present Belgrade with an ultimatum containing demands that were designed to be rejected , which would have ensured a war without the “ odium of attacking Serbia without warning , put her in the wrong ” and ensured that Britain and Romania would remain neutral .