Hello. You did not post the announcements that the question refers to, but I can help you, since the announcements that reflected European views at the time of imperialism, generally displayed obvious ideas about the purity and superiority of the white man and the idea that colonies are dirty places without civilization.
The idea of purity and superiority is related to the idea of the "white man's burden", which was a concept that stated that it was a duty (given by God) to Europeans to "clean up", take Christianity and dominate regions with inferior people , in this case, non-white people who lived in other countries, who were considered unclean and therefore needed to be purified by whites.
In this way, Europeans used a strong racist bias to dominate and enslave peoples of other ethnicities, promoting imperialism while claiming that this was the role that God had assigned to whites in this world.
In 1931 Japan invaded the Chinese in search of raw materials for its growing industry. By 1937 a large section of China was controlled by Japan and war crimes against the Chinese had become fairly common. Many believe that this ended up contributing to the isolation of Japan. This incident is said to have not been authorized by the Japanese government but many say the Japanese troops decided themselves.
