After the Brest-Litovsk Treaty, the Left Socialist-Revolutionaries had abandoned the coalition and increasingly viewed the Bolsheviks as traitors to the revolution. In July 1918, the Left Socialist-Revolutionary Yakov Blumkin assassinated the German ambassador to Russia, Wilhelm von Mirbach, hoping that the ensuing diplomatic incident would lead to a relaunched revolutionary war against Germany. The Left Socialist-Revolutionaries then launched a coup in Moscow, shelling the Kremlin and seizing the city's central post office before being stopped by Trotsky's forces. The party's leaders and many members were arrested and imprisoned, but were treated more leniently than other opponents of the Bolsheviks.