The idea that the internment foiled Japanese espionage and sabotage networks is one used by the likes of Michelle Malkin to defend the internment process. Such an argument does not really stand up to scrutiny. Although it is impossible to prove a negative, the blanket internment of Japanese-Americans and persons of Japanese ancestry was largely divorced from actual security concerns. Many of the principal actors at the time whose job it was to ferret out spy rings such as the FBI and Office of Naval Intelligence (ONI) actually disagreed with the mass internment policies and their counterintelligence operations were independent of internment.

Part of the skepticism about the efficacy of internment was that Japanese intelligence did not really use people of Japanese descent in their operations. The two most prominent spies for Japan in the mid-1930s were two former servicemen, John Semer Farnsworth and Harry Thompson, who sold secrets to Japan. In 1941, the FBI busted a Los Angeles-based spy ring and although two Japanese nationals were in charge of the ring, the bust revealed that the Japanese almost exclusively targeted whites to recruit for espionage work. Such racially-based recruiting was not surprising because long-standing discrimination laws on the West Coast and Hawaii had prevented Japanese from entering into positions of power or authority that would be militarily useful; recruiting Japanese-Americans might have been handy to project California's strawberry futures, but would impart little in the way of the movements of the Pacific Fleet. The Japanese community in the US was by and large was not in a position to be anywhere that was useful from a military standpoint. Most Japanese in the US were employed in agriculture or involved in small businesses that served the Japanese community, hardly sectors of major strategic importance. Moreover, despite US public fears of Axis spy rings and fifth columns, the Axis intelligence services were often an anemic portion of the state apparatus and most intelligence operations focused on gather materials for immediate use.

The 1941 busts allowed the FBI to roll up most of Japan's existing intelligence network in the US. The looming war situation led the FBI also drew up what were called ABC lists of potential Axis agents within the country. A-list individuals would be those who were considered dangerous because of their affiliations with Axis-affiliated organizations like the German-American Bund or the Amur River Society, the B-lists were those who were potentially disloyal, and the C-list composed of people on the fringes of disloyalty. The FBI had considerable assistance in compiling these lists from the leaders of the Japanese-American community. Nonetheless, the ABC lists were quite a large net and tended to haphazardly categorize individuals and in keeping with the Hoover FBI's practices, treated existing legal protections from wiretapping, search and seizure,and detention as minor obstacles.

The extent of cooperation the FBI received from the Japanese-American community leaders as well as the knowledge it gleaned from the 1941 busts meant that it did not anticipate mass disloyalty from this group should war between the US and Japan erupt. Both the FBI and the ONI reports to FDR before Pearl Harbor stressed that mass internment was not necessary and the loyalty of the population was assured. The FBI went into Pearl Harbor with the assumption that the only individuals interned would be those on the ABC lists while the rest of the population would be monitored but not interned.

The bombing of Pearl Harbor helped engender a public hysteria about fifth columns and disloyalty that seeped into a number of areas of the federal government. The FBI's raids on the ABC individuals helped fuel this panic, especially as newspapers reported on FBI busts of equipment like cameras or guns. The military commander of the Western Defense Command, General John L. DeWitt publicly stated that the FBI had found dynamite, radio receivers, and machine guns in these raids. The Department of Justice internal memoranda denied these claims, stating:

We have not found a single machine gun nor have we found any gun in any circumstances indicating that it was helpful to our enemies. We have not found a camera which we have reason to believe was for use in espionage.

Both the FBI and the ONI actively pushed back within the federal bureaucracy against the pressures for mass internment. Cecil Coggins, one of the ONI's station chiefs in Hawaii, argued that cooperation with the community was essential and did a good deal to scuttle mass internment of Hawaii's large Japanese population. Hoover, certainly not a man with progressive leanings on race, wrote to Attorney General Francis Biddle in early 1942 "The necessity for mass evacuation is based primarily upon public and political pressure rather than on factual data."

Hoover's correspondence with Biddle notes that the growing public calls for mass internment were driving policy, not rational concerns. This was in no small measure due to the wartime hysteria over fifth-columns often dovetailed with preexisting discourses on the Yellow Peril and the wider anti-Asian racism of West Coast politics. Opposition to a Asian immigration had been a bipartisan issue for much of the West Coast for the better part of fifty years before the war and thus provided fertile ground for the media to push for mass internment. State and local officials often took initiatives to lay the groundwork for internment and they found a powerful ally in DeWitt. The general was racist even by the standards of the day and his wartime report on internment was so racially inflammatory that it had to be redacted for a more neutrally-sounding document.

There was no silver lining to Japanese internment during the war. It likely did not prevent any mass sabotage or intelligence operations because the Japanese simply did not place a good deal of effort in backing these types of operations. Moreover, for all its faults in terms of civil liberties, Hoover's FBI was adept at breaking those few operations that the Axis intelligence did conduct within the US. Even before Pearl Harbor, federal and military agencies had established a positive working relationship with the leaders of the Japanese-American communities which added to a justifiable feeling of betrayal when mass internment occurred. That the very agencies tasked with conducting America's counter-intelligence operations opposed mass internment in very concrete terms is a testament to the short-sightedness and overreaction that drove the internment process.

Sources

Kumamoto, Bob. "The search for spies: American counterintelligence and the Japanese American community 1931-1942." Amerasia Journal 6, no. 2 (1979): 45-75.

MacDonnell, Francis. Insidious Foes: The Axis Fifth Column and the American Home Front. Guilford, Conn: Lyons Press, 2004.

Ng, Wendy L. Japanese American Internment During World War II: A History and Reference Guide. Westport, Conn: Greenwood Press, 2002.