战争期间哪里会给敌国移民有大规模回去参军的机会？

In addition to being unjustly imprisoned, Japanese Americans, including citizens and those of Japanese descent, faced extremely limited options to leave the US or even their designated camps during WWII. 

Here's a breakdown of the complex situation:

• Limited opportunities to leave the camps (and the country):
  • Relocation to other parts of the US: Incarcerated individuals could, in some cases, leave the camps to pursue higher education or take jobs in areas outside the designated West Coast exclusion zones, notes the National WWII Museum. However, this was often restricted, and leaving the country was generally not permitted.
  • Military Service: Some Japanese American men were allowed to leave the camps to serve in the US military, primarily in segregated units fighting in Europe.
  • Repatriation/Deportation to Japan: A limited number of individuals, including both US citizens and non-citizens, were eventually repatriated or deported to Japan during and after the war. Some Nisei (second-generation Japanese Americans and US citizens) renounced their citizenship, often under duress, to be included in these repatriations.
• Difficulties faced by those seeking to leave or return to Japan:
  • Renunciation of Citizenship: Japanese American citizens wishing to go to Japan were forced to renounce their US citizenship, according to the National Archives.
  • Prejudice and Hostility: Both during and after the war, Japanese Americans faced intense racial prejudice and hostility, making resettlement and rebuilding their lives challenging, notes the National WWII Museum.
  • Legal Obstacles: Legal battles challenging the internment and denaturalization processes were ongoing for years, highlighting the injustices faced by Japanese Americans, says UCLA's Asian American Studies Center. 

In summary, leaving the US was a highly restricted and complex endeavor for Japanese Americans during WWII. While some avenues existed for leaving the camps to work or serve in the military, leaving the country was far more limited and often involved renouncing one's citizenship under difficult circumstances.