Japanese American units of World War II

The Impact of Pearl Harbor on Japanese Americans in Hawaii: Insights from Mark Matsunaga

When Japanese warplanes attacked Oahu on December 7, 1941, about 2,000 Americans of Japanese ancestry (AJAs) were on Army active duty in Hawaii. Hundreds more were University of Hawaii ROTC cadets who answered the call to arms that day with the Hawaii Territorial Guard.

At the time, Hawaii’s population was about 425,000, and Japanese were the largest ethnic group. Three-fourths of them were U.S.-born citizens, or Nisei.

The shock of Pearl Harbor bred wild rumors that local Japanese aided the enemy. The official history, Hawaii’s War Years, later concluded:

“Despite the beliefs to which some people still cling, all the investigative agencies are agreed that espionage in Hawaii before the war was carried on only by the Japanese consular staff and one other person, a German. They also agree that there was no espionage after the start of the war, no sabotage, no fifth column activity of any sort.”

Immediately after Pearl Harbor, however, fear and suspicion ruled. More than 110,000 Japanese were removed from the West Coast and locked up. In Hawaii, more than 1,500 were arrested and relocated. For two years, AJAs were reclassified by Selective Service officials as “enemy aliens” and were not eligible for the draft, although they were allowed to volunteer for racially segregated units. The Navy and Marine Corps did not enlist Nisei during the war but made wide use of them in the Pacific.

World War II Units Primarily Made Up of AJAs:

100th Infantry Battalion:
A year before Pearl Harbor, America began drafting men for the military and activating National Guard units. As a result, about half of Hawaii’s newly federalized 298th and 299th Infantry regiments were AJA draftees or volunteers. In May 1942, these 1,400 Nisei were removed from their units and organized into a separate battalion. During the Battle of Midway, they were sent from Hawaii to Camp McCoy, Wisconsin, where they became the 100th Infantry Battalion (Separate) and adopted the motto, “Remember Pearl Harbor.”

After more than a year, the 100th was sent to North Africa and then Italy, entering combat near Salerno in September 1943. Attached to the 34th Infantry Division, the 100th earned respect and the nickname “The Purple Heart Battalion,”in fierce fighting at the Rapido River and Monte Cassino. The battalion received replacements of Hawaii and Mainland AJAs from the 442nd Regimental Combat Team, which arrived in Italy in June 1944. The 100th maintained its unique designation and identity and earned three Presidential Unit Citations.

Today’s 100th/442nd is the Army Reserve’s only combat arms unit.

Military Intelligence Service (MIS):

About 6,000 AJAs – roughly half of them from Hawaii – served with the Army’s Military Intelligence Service in the war against their parents’ homeland or in the postwar occupation. Armed with knowledge of the enemy’s language and customs, they served as interpreters, translators, POW interrogators, propagandists, electronic eavesdroppers, spies, guerilla leaders, cave flushers, and combat infantrymen. Most trained at the MIS Language School in Minnesota.

Beginning with Guadalcanal in 1942, MIS AJAs fought in every major battle in the war against Japan, often risking being mistaken for the enemy by fellow GIs. The MIS Nisei were credited with saving countless lives and shortening the war. Afterward, they played key roles in the occupation of Japan, helping to create the modern democracy that emerged. MIS work went unheralded for years due to the classified nature of their missions and lack of records. In 2000, the MIS received a Presidential Unit Citation.

442nd Regimental Combat Team:

Six weeks after Pearl Harbor, the Hawaii Territorial Guard dismissed all of its Nisei members. Rather than accept rejection, 169 of them organized as the Varsity Victory Volunteers (VVV) and performed manual labor for the Army for nearly a year. Their efforts, along with the excellent records of the MIS and 100th Battalion, led the War Department to call for volunteers in early 1943 to form a 4,500-man AJA regimental combat team. Nearly 10,000 volunteered from Hawaii, but only 1,200 from the Mainland, where many Japanese Americans were interned.

The 442nd trained in Mississippi, deployed to Italy in mid-1944, and later joined the 100th Battalion. The team’s components included infantry, field artillery, combat engineers, and other support units. The 442nd fought gallantly in Italy and France, rescuing the “Lost Battalion” and liberating Dachau concentration camp inmates. The 442nd became the most-decorated unit in U.S. history for its size and length of service, earning seven Presidential Unit Citations and 21 Medals of Honor.

1399th Engineer Construction Battalion:

More than 1,000 AJAs served in the 1399th, which remained in Hawaii during the war, constructing 54 major military projects. A plan to deploy the unit to the Philippines was vetoed by the War Department because of its critical work in Hawaii. The 1399th earned a Meritorious Service Award in 1945.

Ethnic Japanese made up 37 percent of Hawaii’s 1940 population, and AJAs accounted for over 62 percent of the 806 Hawaii residents killed in service during World War II. In July 1946, President Harry Truman greeted the 442nd RCT at the White House and said:

“You fought not only the enemy, but you fought prejudice, and you have won. Keep up that fight, and we will continue to win--to make this great Republic stand for just what the Constitution says it stands for: the welfare of all the people all the time.”

Two years later, Truman ordered an end to racial segregation in the military. Nisei veterans came home to help change both the nation and Hawaii, overcoming political obstacles to statehood. Prominent Nisei veterans included U.S. Senators Daniel Inouye (442nd) and Spark Matsunaga (100th) and Governor George Ariyoshi (MIS).

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© Mark Matsunaga, PHP, August 10, 2016
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