Perhaps looking at this from another angle, might we consider the Prime Directive as a candidate for elevation here? So often it's directly involved in an episode or program development, or its presence undergirds whatever's the device forwarding the plot so integrally that it indeed serves as the proverbial 800 lb. gorilla in the room.
But are there instances where the PD is nominally a driver, but in fact is really just a convenient or recognizable figleaf that might obscure the fact that the meat of the piece cardinally concerns a clash of strong personalities, trenchant social commentary, or a morality tale?
Of course the Directive and its consequences are writ large on the face of A Private Little War. But I believe that the intent of the screenplay's author wasn't that the audience's perception be that the episode happened to tangentially reference Vietnam, but rather that it unambiguously represent a pretty clear statement Trek was making on the subject.
I might be rather simplistic with this example, but can one cite others that might make such a case for the PD acting as the, uh, Phantom Menace?
