I have a collection of Joyce Carol Oates short stories that I bought a while back so I could have a hard copy of "Where Are You Going, Where Have You Been?" to annotate for my classroom.  This collection, entitled Where Are You Going, Where Have You Been?: Selected Early Stories by Joyce Carol Oates also features the story that you are looking for, "First Views of the Enemy."  I checked to see if it were still in print on Amazon (probably could find it from any number of vendors), but it was still in stock, even though my edition was published in 1994.  I was sure that there are probably even newer collections out there, and there was a more recent one-- Faithless:  Tales of Transgressions (2002).