Richard:
Many find the term "Jap" to be offensive like the "N" word. My wife is from Japan. She was selected as US Air Force Family Services volunteer of the year in 1973 and served as a US Air Force volunteer for more than 20 years. She served as a volunteer at the Tripler Army Hospital while I served in Vietnam. My NCOIC in Vietnam was a Japanese-American who received a Purple Heart and Bronze Star while serving as a combat photographer.
The Japanese-American unit in WWII was the most decorated unit in the Army and Senator Daniel Inouye received the Metal Of Honor and I do not think they would appreciate that term. I do wish we could get away from racial slurs in this country, but perhaps that is just wishful thinking.