Due to the perception of “public danger,” multiple Japanese citizens living in the US were detained and persecuted at various distances from the Pacific coast. If they could not dispose of or take care of their property within a few days, everything they had would be lost forever. The fact that Japanese Americans were interned is directly related to the attack on Pearl Harbor.
As a result of the attack, the United States was wholly trapped in two theaters of war in World War II. Before Pearl Harbor, the United States was only involved in the European war, supplying Britain and other anti-fascist countries in Europe with ammunition. The attack on Pearl Harbor also sparked national security concerns, especially on the west coast.
Another possible reason for the targeted internment is racism. According to researchers, one of the causes of such a selective hatred toward American Japanese is discrimination and the racial connotation of the conflict. This, in addition to the fact that Italians and Germans did not physically invade the US, could have been a secondary triggering factor.
Identifying a Japanese person was much easier for the general population in comparison to Germans, whose Caucasian appearance did not contrast with that of the majority of Americans. Thus, it could be the case that the highlighted presence of Japanese Americans, who people associated with the recent Pearl Harbor attack, was a significant reason for the targeted isolation of this community.
During the war, the US authorities detained more than 10,000 American Germans who did not actively participate in the war. The authorities dealt with the cases of German citizens individually, and relatively few of them were held in internment camps run by the Ministry of Justice in connection with its duties under the Enemy Aliens Act. This highlights the difference between how the authorities handled Japanese and other citizens. However, like Italy, Germany did not invade the United States and did not claim it.
Moreover, racial bias was another reason for such targeted internment. For these reasons, Americans of Italian and German descent escaped mass arrests during the war, unlike the Japanese.