Why were Japanese internment camps instituted on world war 2?

Answer 1

Fear of possible spies and "Fifth Columnists" among the Japanese population on the US West Coast. These Japanese Americans were immigrants and their children, and many still retained much of their Japanese culture. Only a year or two earlier Fifth Columnists in Norway had helped the Nazis take over Norway after an invasion. There were fears the Japanese might invade the West Coast. The Japanese never had any plan to do so, but no one in the US knew that at the time. It was only Japanese-Americans living in the West Coast states who were interned, though this was where most of them did live. Any others living in scattered families in the central and eastern states were not interned. In Hawaii people of Japanese ancestry were close to half the population, and they also were not interned in camps. Another reason given at the time was that forcing the Japanese-Americans into camps was "for their own protection". There had been a rash of attacks by outraged citizens in the month or two after Pearl Harbor on any Asian person handy - most of whom turned out to be Chinese. This was truly monumentally moronic, since the conflict between the Japanese and the US was over the Japanese invasion of China. But to patriotism-blinded self-appointed vigilantes, they all looked alike. Something similar happened after 9/11, when Muslims in general and anyone wearing a turban (such as Sikhs) in the US were liable to be attacked by the same sort of ignoramuses.