War Games by Jodie Bishop 1989, Paperback OUT OF PRINT
"A group of college students volunteer for a summer with the national guard for war games. Aleksander is appointed the leader in"of the red team" and Kelly of the blue. Let the games begin. And they do. With everyone making out with everyone else and in the middle are Mitchel and Andrews who learn that there are other games to be played on a make believe field of battle. "