What are the main causes of Japanese internment camps?

The United States placed Japanese Americans into internment camps during World War II because of fear that those with ethnic and cultural ties to Japan would aide Japan's cause in the war. After the surprising attack on Pearl Harbor, the American government (as well as many Americans) worried about Japanese threats and doubted the loyalty of Japanese Americans. - Enotes Website

The Japaneese bombed pear harbour, so we took action to ensure no spies