The way Stripes struggles and kills his first roach, in a "tug war" with a knife pinning eachtother to the ground, is a reference to the same way an ironically unamed german soldier manages to drive a knife thru Mellish. "Saving Private Ryan" being a movie with a very clearcut dehumanization of the enemies from a real war also rooted in eugenic ideals, makes it a great paratext to the thesis of the episode.
Spoiler: Episode is similar to "Hearts and Minds"(Outer Limits 4.3) where soldiers have their perceptions of the enemy changed by their command to see them as inhuman.