Japanese internment was the relocation and internment of Japanese Americans by the U.S. government in response to the attack on Pearl Harbor. Approximately 110,000 Japanese were imprisoned throughout the American West at approximately ten camps run by the War Relocation Administration. They were held until the war turned in favor of the U.S. and then slowly released.
Internment had several effects on the U.S. There were several Supreme Court cases that still affect the U.S. today. The cases Hirabayashi v. United States and Korematsu v. United States, which both ruled that internment was a “necessity”, have since been overturned by other judicial proceedings. These two cases led to the Civil Liberties Act of 1988, which was aimed at preventing future internment based on race or ethnicity. Some people have mentioned this case in light of the imprisoning of Guantanamo Bay detainees. Internment and the issues of government powers in wartime have taken on a new meaning due to recent development in the War on Terror.
Japan was affected by internment in some way to. After and during the war, there was a large repatriation effort by internees who felt betrayed by the U.S. Many American-born Japanese, enraged that they had done nothing wrong and were still forced into the camps, left for Japan and never returned to the U.S. These American-born Japanese were generally looked down upon by native Japanese, adding to the suffering they endured. I couldn’t find any exampled of this being used as propoganda by the Japanese government (something along the lines of “look what the evil Americans are doing to our Japanese brothers”) but it is possible the imperial government did have knowledge gained from repatriated Japanese.