Morning: Mensdorff gives Grey an outline of the Austrian note to Serbia mentioning it would have something in the nature of a time limit. To Grey’s concern it is thus really an ultimatum.
Grey remarks everything depends on convincing Russia of the justice of Austria’s demands and on whether the demands can be accepted by Serbia.
He also tells Mensdorff it would be terrible if the four great powers – Austria-Hungary, Germany, Russia and France – were involved in war. Naming just these four powers implies Britain will remain neutral in a European war.