In the final days of the Second World War, the Soviet Union broke its neutrality pact with Japan, declaring war. The Soviets invaded Manchuria on 9 August, and overran the Japanese in less than 11 days. The aftermath was appalling; Japanese casualties were tenfold than that of the Soviets'; both civilians and wounded Japanese soldiers were left to die while the army retreated; and many Japanese civilians committed mass suicide. It was in this carnage that Dōshin Sō recognized and understood the "nature of the human being". According to his book, the nature and quality of the person is extremely important since politics, law, and day-to-day living are all conducted by human beings.