“Arena” - Kirk is certainly not breaking the Prime Directive by going after the Gorns with intent to destroy because the Gorns had already destroyed Cestus III. The only reason he was stopped was because they crossed into the Metron star system.
“The Return Of The Archons” - If Kirk could have left the planet with an explanation for what happened to Sulu and O'Neal and the Enterprise had not been attacked then he probably would have left Beta III as is for Federation sociologists to return to and study. The inhabitants already knew about "Archons" and themselves were already trying to resist Landru in their own limited fashion.
“A Taste Of Armageddon” - Kirk approaches Eminiar 7 under protest and he would have gladly left the two warring planets to themselves and their war until Eminiar tries to destroy Kirk, his crew and his ship and thereby drag the Federation into their interplanetary conflict. I don't think the Prime Directive is going to hold a lot of water when it comes to open aggression from an advanced space faring culture.
“Friday’s Child” - No Prime Directive violation since the natives were already aware of and trading with "Earth men." And Kirk didn't try to interfere in how they managed their affairs, but just tried to survive until the Enterprise returned. He might have overstepped in not leaving Eleen behind to face her fate.
“The Apple” - Kirk is ready to bug out and leave the planet except that Vaal has no intention of letting them leave...alive. Kirk also had orders to contact the inhabitants if dictated. Unfortunately no information is given in this episode to explain how the natives had gotten into their situation with Vaal, but it's evident enough that an advanced someone had put them there. And it's been said enough that the Prime Directive applies to a growing and developing culture...which the natives certainly were not.
“Bread And Circuses” - All Kirk and company do here is survive and escape. And Merrick didn't so much influence the inhabitants but rather just surrendered to them. And it seems the Proconsul and what few others may have know something about where these strangers came from were keeping a lid on it themselves.
“A Private Little War” - It's supposed to be a "hands off" planet by Federation/Klingon treaty and yet the Klingons are certainly violating it. Kirk certainly doesn't like having to get involved, but the end result is clear if nothing is done: the hill people are going to be wiped out by the villagers with the Klingons behind it all. Kirk could just report it, but before that he decides to level the playing field for the hill people. What he doesn't do is introduce superior technology. I'd say this is Kirk's closest instance of putting his foot in it, but evidently the Federation lets him off and retain his command and career. But sadly we never hear what happens afterward to the people of Neral.
“The Gamesters Of Triskelion” - The Providers, an advanced species, forcibly kidnap Kirk's landing party and intend to destroy the Enterprise. They're certainly, and admittedly, not interested in fostering a developed society until Kirk challenges them. And they still could have gone back on their word and destroyed Kirk and the Enterprise. I certainly don't think the PD applies here.
“A Piece Of The Action” - Never mind this is something of a silly episode. The Horizon had already contaminated the planet most likely long before the Prime Directive existed. I suspect if Kirk had been able to ascertain the situation and leave peaceably to report what he'd found he would of. But once again the landing party is taken hostage and threatened. In this case, though, it seems to say that the Federation is taking responsibility for what happened to the Iotians and Kirk's action is the first step in trying to minimize or partially reverse the Horizon's contamination...whether you agree or not with his idea.
“Patterns Of Force” - They're trying to find out what happened to John Gill and later do learn what happened to him and that Gill had violated the Prime Directive. Kirk's intent throughout seems mainly to be to find Gill and bug out, but when he learns what's happened he manages to help Gill call off the attack on Zaon just before Gill is killed. They leave immediately after. And note that the Ekosians already seem to have some awareness of other worlds beyond theirs and Zaon.
“The Omega Glory” - Tracey has already violated the Prime Directive by introducing advanced weaponry into killing thousands of Kohms. Kirk is just trying to survive yet without doing the same thing. The question is whether Krik violated the Prime Directive by simply explaining the meaning of the Yangs' own sacred text.
“Spock’s Brain” - It may seem silly, but is there really a Prime Directive violation for retrieving Spock's brain back from the Morg women after they had stolen it?
“For The World Is Hollow And I Have Touched The Sky” - Kirk is trying to put Yonada back on course and reveals a "truth" that the Yonadans had sadly forgotten, but would have been revealed again once they reached their destination.
"The Cloud Minders" For me the real question is how can the Federation allow membership to a world which clearly exploits some of its own people. Anyway the episode raises the question as to whether Kirk oversteps into Ardanan jurisdiction by offering the Troglodites filter masks. Evidently the Ardanans aren't "doing all they can" to secure the zenite and fulfill their responsibilities to another Federation member world.
“One Of Our Planets Is Missing” - The message here seems to be take a really good look before you eat another planet."
“The Infinite Vulcan” - The Phylosians were about to launch an interstellar war out of exaggerated gratitude to Stavos Keniclius for saving them from a disease or something. And the Phylosians evidently knew about alien life and other worlds.
“BEM” - Kirk just wanted to bug out, but Ambassador Bem kept screwing things up. If anything Bem is to one who should be on the hot seat.
The issue seems to come down to:
- what constitutes interference and when does it apply?
- what is reasonable and accepted action in the event of evident prior interference or contamination?
- when and where does non-interference apply?
The Prime Directive is evidently not an absolute blanket policy with no exceptions. If this is drafted up by politicians and legal minds, no matter how well meaning, then it's most likely going to have a lot of room for interpretation. The whole idea seems to be extrapolated from past encounters in our own history where less advanced cultures were grossly exploited by more advanced ones, in terms of technologically advanced and not necessarily ethically advanced. But on a planet where there's no where else to go it's inevitable that cultures will clash on some level. Putting this on an interstellar scale obviously you've got a lot more room to play with, but there are likely still going to be instances of cultural conflict. In the end much is going to depend upon the value ascribed to a given species and culture.
The Klingons certainly have no qualms about contaminating another world because they see themselves as having a manifest destiny to conquer and rule because they are strong and aggressive by nature. To them it's self-evident. In some respects the Klingons are much like past cultures on Earth such as the Romans and others. Same for the Romulans. And it's probably partly why the Federation is bothered by them because the Klingons remind them of what they used to be like and in many ways could still be just under the surface. Kor was actually quite right in his own way.
The Prime Directive (as it seems to exist in the TOS era) appears to be the first steps in trying to curb exploitation of other species and cultures, an effort not to repeat the mistakes of the past. I don't think it's meant to eliminate all interaction, but primarily to minimize detrimental interaction.
If a species is isolated and has absolutely no knowledge of other worlds and other life, and even if they are actively looking out into space and listening (as we are), and even making their first forays off planet (as we are) then the idea seems to be to still not reveal yourself to them. The idea of subspace radio also seems to suggest that it isn't something that could be easily tapped into without a sufficiently advanced technology. Subspace radio is not only convenient (and necessary) for interstellar activity, but it has a side benefit of keeping you hidden from less advanced cultures. I'd say even if they manage early warp flight I'd think it best if they find you on their own rather than you going to their home world to announce yourself. A race could still feel quite threatened by someone with really advanced technology suddenly showing up on their doorstep. TNG's episode "First Contact" seems to show that well enough. I also think the Vulcans showing up as they do in the TNG film First Contact wasn't that bright an idea. I guess they didn't yet have a version of the Prime Directive---not very enlightened I'd say.
Now if you do happen to encounter primitive or less advance inhabitants then you seem to have to make a genuine effort not to reveal who you really are and where you come from. The exceptions to this seem to apply to those worlds that where contact already existed before the Prime Directive policy was introduced. If prior contamination is evident then you appear to have some latitude to reverse or minimize the contamination.
If you encounter a sufficiently advanced culture who don't conform to Federation standards and principles you're still not supposed to interfere in their affairs. But that doesn't mean you have to sacrifice yourself to them. You are authorized to take reasonable measures for self-defense and self-preservation.
Under normal circumstances you're not to interfere in the internal affairs of a Federation member world. But what if that member world's internal affairs are adversely influencing or affecting another member? Where do their rights end and another's begin? And this issue gets into the area of what are the standards for Federation membership, but that's another discussion.
All life has value, but the questions arise when it comes to how much value a species or culture is given. Certainly the Federation worlds have value and a right to exist just as much as less advanced worlds. How much is the Federation supposed or expected to sacrifice in the name of protecting another culture?
And finally what exactly are the conditions where a Starfleet or starship commander must be willing to sacrifice himself, his ship and his crew to uphold the Prime Directive? This is never really spelled out in Star Trek as far as I know.