Farang Noi is the term I heard quite often about my son.
As for the Army cadets, on children's day several years back they took my son's class to the Udon Thani air base for a show and tell.
My son, Thai, Canadian, light skinned, looks very much like me, fluent Thai speaker was not allowed on the base, pure bloods only.
If drafted he could not become an officer, pure bloods only.
Glad we've moved back to Canada