I afraid I have to disagree with some of the things you said about the Japanese Americans during WWII.
For example it should be known that in Strangers From A Different Shore by Ronald Takaki (pages 397-404), it states at least 33,000 Japanese-Americans served in the U.S. Armed Forces.
You can also get more details and information about Japanese American history and combat experience by reading the book Honor By Fire by Lyn Crost.
It tells about the various accounts of Japanese-American military veterans who served with U.S. forces (pages 311-315) in Italy, Western Europe, Southeast Asia and in the Pacific during WWII.
On pages 311-315 the book shows that they served in the 100th Infantry Battalion and 442nd Regimental Combat Team, Military Intelligence Service, various U.S. Marine divisions, United States Navy, and etc.
This book also shows on pages 31-33 that in September, 1942, U.S. General Douglas MacArthur actually had started to recruit Japanese Americans from DETENTION CAMPS and Hawaii to serve in the Allied Translator and Interpreter Section (ATIS) to perform various intelligence duties.