How did Roosevelt justify the relocation of people Japanese ancestry?

President Franklin D. Roosevelt did not justify the relocation of people of Japanese ancestry during World War II. He instead issued Executive Order 9066, which authorized the military to establish military zones and to exclude any persons from those areas. The government then used this order to forcibly remove and incarcerate over 120,000 Japanese Americans, the majority of whom were American citizens, from the West Coast of the United States.