You are need to look at them they way they tended to look at themselves to understand.
They were not Americans of Japanese ancestry they were Japanese who were born in the Japanese Colonies that happen to be on American soil.
They were all either Japanese or Duel Citizens.
Was it nice? No.
Was it necessary?
Probably.
They were colonist.
No, not all Japanese-Americans were dual citizens. I agree with Sen. Robert A. Taft (R-Ohio) and J. Edgar Hoover that interning Japanese-Americans was not only unnecessary but in fact, a travesty.