The crime used to justify internment during World War II was espionage and sabotage, particularly after the attack on Pearl Harbor. The fear of Japanese Americans being loyal to Japan and a potential threat to national security led to their forced removal and imprisonment in internment camps.
policies based on racist ideas.
Tragic: It was considered tragic because the government imprisoned and monitored people who were guilty of no crime. They were imprisoned for purely racial reasons and based on irrational fears of possible damage. Nobody should have their life destroyed due to irrational fears of what they might do.
Dangerous: It sets the precedent that such wildly intolerant conduct could be repeated.