The Germans declared the war the moment the Japanese attacked, dont be ridiculous.
There were also intelligence reports stating that the Japanese were not a threat.
In early 1941, President Roosevelt secretly commissioned a study to assess the possibility that Japanese Americans would pose a threat to U.S. security. The report, submitted exactly one month before Pearl Harbor was bombed, found that, "There will be no armed uprising of Japanese" in the United States. "For the most part," the Munson Report said, "the local Japanese are loyal to the United States or, at worst, hope that by remaining quiet they can avoid concentration camps or irresponsible mobs."[3] A second investigation started in 1940, written by Naval Intelligence officer Kenneth Ringle and submitted in January 1942, likewise found no evidence of fifth column activity and urged against mass incarceration.[5] Both were ignored.
When did the War Room became this fucking racist.
Also im pretty sure that it was wildly illegal to do so.