Nazi Germany had to decide who was and who wasn't a Jew in order to know who could be targeted under its racial laws.
The United States had to make the same sort of decision about who was and who wasn't "Japanese."
Who do you think was stricter?
Obviously, I wouldn't be asking the question if the answer weren't surprising: the United States was stricter. By a lot.
Under the Nuremberg Laws, a person with at least three Jewish grandparents was a Jew, no further questions asked. A person with only two Jewish grandparents was a Jew only if certain further conditions were met.
The rule in the United States was that any person with a Japanese ancestor was Japanese. Regardless of degree.
U.S. Army Western Defense Command, "Japanese Evacuation from the West Coast, 1942: Final Report," p. 514.
And in actual operation the rules on curfew, exclusion, and detention touched people who had only one Japanese great-grandparent.
Final Report, p. 145.
This is a question (who was "Japanese" for the purposes of internment?) that is often asked but surprisingly hard to find the answer to. So I thought I'd share it here.