During World War II, second-generation
Japanese Americans (Nisei) served in the
Military Intelligence Service (MIS), performing
secret intelligence work against the Japanese
military. Their work dispelled any doubt that, as
Americans, they were willing to fight an enemy
with whom they shared ancestry.
On November 1, 1941, the U.S. Army opened
a MIS Language School at the Presidio in
San Francisco. The secret mission: to teach
the Japanese language to military intelligence
personnel in the event of war with Japan.
Following the outbreak of World War II,
Japanese Americans with the required language
background were recruited from the 100th
Battalion, 442nd RCT, and from Hawaii and
America’s camps. In all, 6,000 Nisei graduated
from military language schools at the Presidio,
and at Camp Savage and Fort Snelling in
The MIS graduates were dispatched to every
combat theater and participated in every major
battle and invasion against the Japanese military.
They were attached to the U.S. Army, Navy,
Marines and Air Corps and ‘loaned’ to British,
Australian, Canadian, New Zealand, Chinese and
Indian combat units in every phase of the Asia-
Pacific war until Japan was defeated.
Beginning in May 1942, MIS participated in:
The Nisei linguists:
- The Aleutian and Solomon Islands invasions
- The drive through New Guinea and the
- The Central Pacific invasions of Tarawa,
Kwajalein, Majuro, Eniwetok, Saipan and
- The final assault on Iwo Jima and Okinawa
- Reopening the Burma Road to China
Translated enemy documents, including orders, battle plans, maps, diaries and letters
- Interrogated Japanese Prisoners of War
- Served undercover in Japan-occupied Manila
- Served as order-of-battle specialists
- Intercepted and deciphered enemy communications
- Composed and broadcast surrender appeals
and other psychological warfare tactics
- Flushed caves of enemy soldiers and civilians
They gathered volumes of intelligence in the
process, which were used to develop successful
Allied strategies and operations against the
Nisei served in front line combat units and were
awarded the Combat Infantryman’s Badge. They
fought as ferociously against the Japanese as the
100th Battalion and 442nd Regimental Combat
Team fought in Italy and France.
When the Pacific war ended, they helped
demobilize Japanese armed forces and create an
industrialized Japan allied to the United States.
An additional 3,000 Nisei linguists served in the
Occupation of Japan in various capacities. They
helped write Japan’s Constitution and aided in
reform movements involving education, politics
and women’s rights.
With their knowledge of the Japanese language
and customs, the Nisei served as a bridge
between the Japanese officials who did not speak
English and the American officials who did not
Until recently, very little was known about the
invaluable service provided by the Nisei of the
MIS, primarily because their work was strictly
The Nisei who served in the MIS were America’s
secret weapon in the war against Japan. MG
Charles Willoughby, G-2 Chief in the Pacific,
credited them with saving a million lives.
In 2000, the MIS earned their Presidential Unit Citation (right) for extraordinary heroism in military operations against an armed enemy.