At dawn on December 7, 1941, the Japanese military attacked the U.S. Naval base at Pearl Harbor, Hawai’i. Later that day, Franklin D. Roosevelt issued Presidential Proclamation #2525, authorizing FBI agents to apprehend any Japanese alien fourteen years or older. On the following day, the President issued similar proclamations against German and Italian aliens (#2526 and #2527), and declared war on Japan. Overnight, a million law-abiding immigrants were transformed into “enemy aliens,” based solely on their country of origin. On December 11, Germany and Italy declared war on the United States.

The Justice Department’s apprehension and detention of thousands of Japanese, Germans, and Italians was authorized by the Alien Enemies Act of 1918 – U.S. Code, Title 50, Sections 21-24. Based on the 1798 Alien and Sedition Acts, this law specifies that citizens (age 14 and over) of enemy nations can be “apprehended, restrained, secured and removed” in case of declared war, or actual or threatened “invasion or predatory incursion” by a foreign nation. No explicit distinction is made between resident immigrants and aliens in the U.S. on a temporary basis.

The records on the interned “dangerous enemy aliens” contain no specific evidence of subversive activities against the United States. In fact, evidence that Japanese aliens were not a threat was available but suppressed. For example, a 1941 FBI break-in at the Japanese Consulate in Los Angeles discovered memos indicating that the Japanese government considered Japanese immigrants and Japanese Americans to be cultural traitors and therefore unreliable. Japan did not trust any aid or information from Japanese immigrants.

For two months preceding Pearl Harbor, State Department representative Curtis Munson conducted an exhaustive investigation of the Japanese community on the West Coast and Hawai’i that included review of the intelligence reports from the previous ten years. The 25-page Munson Report concluded that “there is no Japanese problem.” For the most part, the report read like a tribute to the moral character and loyalty of Japanese Americans. It was quietly ignored.

On the day Pearl Harbor was attacked, the lists that U.S. intelligence agencies had compiled for years were put into effect. By nightfall, before the U.S. had even formally declared war, FBI and other agents of the U.S. government descended upon the homes and businesses of Japanese, German, and Italian immigrants. The aliens’ homes were searched and possessions seized. Some were apprehended and detained without explanation, on grounds determined solely by the FBI. Families had no idea where their loved ones were taken, or why.

By December 10, only three days after Pearl Harbor, 3,846 Japanese, Germans, and Italians had been apprehended, charged with no crime. Local FBI agents especially targeted community and religious leaders; people with business, cultural, or political ties to their home country; editors/publishers of Japanese, German, and Italian language newspapers; and teachers at language schools.

The United States went outside its own borders into countries not at war, citing a threat to national security or to obtain hostages to trade for U.S. citizens stranded in war zones. Many Latin American governments went along with this for reasons of their own, although records indicate they did not believe that their Axis residents posed a serious internal or continental threat. Under a previous arrangement with the U.S., Panamanian officials apprehended persons of Japanese, German, and Italian ancestry and detained them at a U.S. military facility.