 These had to do with the increasing violence against Christian missionaries and converts within the Chinese interior, which after the Second Opium War in 1860 had been opened up to westerners.As Korea was a vassal state of China, the massacre of westerners and Christians in Korea was seen within the context of anti-Western behavior in China by diplomatic and military authorities in the west.Many believed a firm response to such acts of violence was necessary to maintain national prestige and authority.