Answer:
The answer is: Roosevelt felt that the order was necessary to protect the nation from Japanese spies.
Step-by-step explanation:
Executive Order 9066 was issued by President Franklin D. Roosevelt after the "Pearl Harbor" was bombed by the Japanese. The order removed the resident enemy aliens from the military areas. The reason behind this was the protection of the nation from Japanese spies. So, this moved the Japanese-Americans in the camps. These people endured the harsh treatment coming from the American military guards. The order was also questioned by Justice Frank Murphy as a sign of racism.
It turned out that the spies who were caught were actually Americans (10 of them). None of them even came from Japanese ancestry.
Thus, this explains the answer.