Answer:
Kaiser was referring to the Murder of Archduke Francis Ferdinand in Serbia
Step-by-step explanation:
The action of Austria against Serbia was creating a bad impression in Russia and this made the Russian Tsar, to send a telegram message to Kaiser asking for this intervention to avoid a looming war in Europe. It caused a bad impression on Russia because of its ties with Serbia.
The Russians had a very different opinion about the murder of Archduke Francis Ferdinand by his own countrymen in Serbia and the punishment that should be meted out on those who committed the murder of the king and his immediate family. the killing of Archduke Francis Ferdinand was one of the major causes of the World war 1