Digital History>eXplorations>Japanese American Internment>The Decision to Intern>Attack on Pearl Harbor

Attack on Pearl Harbor: Report of the Commission Appointed by the President of the United States to Investigate and Report the Facts Relating to the Attack Made by Japanese Armed Forces Upon Pearl Harbor in the Territory of Hawaii on December 7, 1941 [Roberts Commission, named after U.S. Supreme Court Justice Owen Roberts],

January 23, 1942

There were, prior to December 7, 1941, Japanese spies on the island of Oahu. Some were Japanese consular agents and others were persons having no open relations with the Japanese foreign service. These spies collected and, through various channels transmitted, information to the Japanese Empire respecting the military and naval establishments and dispositions on the island.