Answer: Authority and Social Proof
Explanation: The Japanese Internment in the U.S. occurred during World War II. It was an effort to prevent Japanese Americans from becoming spies and put over a 100,000 people of Japanese ancestry in internment camps.
Compliance without pressure is obeying a request without any visible pressure form an external body.
The compliance without pressure techniques that were responsible for neighbors not protesting this action although it was clearly wrong are Authority and Social Proof.
Authority: removes our moral obligation. We feel compelled to comply with the order because it came from a figure of authority.
Social Proof: We feel compelled to comply because others are doing so. if we see others protesting, we may also consider the need to protest the order.