I think Michelle explains what was going on pretty well--- the author of the memo apprenetly wanted to justify why he was having so much food distibuted to the afore-mentioned Japanese Americans.
Incidentally, my impression is that Ken Masugi of the Claremont Institute, is, I think the most authoritative expert on this (as he is on more than one thing).
http://internmentarchives.com/showdoc.php?docid=00205&search_id=2749&pagenum=3
Whew! Masugi's phrase Irish-Americans initially caught my eye making me fear the worst (yet another public scolding for America's former Irish need not apply discrimination). Never fear! Instead Masugi merely observes "Irish-Americans have often been opposed to American foreign policy, which has often alined [sic] itself with the British."