Didn't Kirk give weapons to a native tribe in TOS to help them fight their enemies, who I think the Klingon's were arming? You can probably argue something about the show not quite having the prime directive down, and it was followed much less religiously back then, but it was still something. I could understand a SF captain going the route they do in DH, though.
Note: Below is a large post that is basically my thoughts about the prime directive, so its only kind of related to dragon's Honor, although its still a Trek thing and involved with Trek in general, and this book. Its a big post, so if you don't care about the SF Prime Directive, or atleast my thoughts, then you can just skip the rest of this post. But, once thinking about it because of this topic, I felt the need to talk about it.
That leads me to something that is my biggest problem with Starfleet, the more modern interpretation of the prime directive. The Prime Directive pretty much became an excuse for SF captain's to just watch atrocities and tell themselves they were doing the right thing. Back in Kirk's day, if an asteroid was heading towards a planet (a completely natural thing, an alien didn't shoot it at the planet) Kirk and crew would try to stop it. There is no way any of the other crews would do that. Heck, I can think of two times in ST where a captain would rather watch a whole world die and then talk about how it was better to let them die then interfere. If the choice is between saving people from a natural disaster that would cause their extinction, SF says itís better to let them all die, because even the chance that they could see advanced technology would somehow be a fate worse than death.
TNG's Homeworld is the biggest example of it. Picard is my favorite Captain, but this, to me, made me see him in a new light, and not a good one. In this situation, Kirk was in that situation (and had a ship capable of what the ENT-D was capable of doing for the people, i.e. transporters and holodecks) he would have done it without a second thought. Picard was willing to allow an entire people to die for ideals I'm sure were not the main point of the prime directive. You could probably argue in favor of his actions, use some weird example about how seeing aliens/tech too early is a fate worse than death, but it would only be isolated incidents. Most of the time, extinction is going to be worse than anything breaking the PD would cause. Worf's brother was the only one who acted ethically in that episode, and did something the other supposedly "evolved" humans in Star Fleet wouldn't do.
Oh, humans have "gotten rid of" the desire for material possessions (that is also stupid, and DS9 had a great scene mocking that idea with Jake and Nog in an episode whose title I can't remember), but they're willing to stand by and watch an entire race die because even the risk of seeing technology would ruin the culture so much that extinction would be preferable. At least Janeway (in "Time and Again") had the excuse that the people did it to themselves. Even then, I'd say that allowing an entire world to die is far worse than anything revealing their presence could do. The aliens in Homeworld were going to be killed by basically an act of god. Sure, some people die like that, but I think that it would be the responsibility of an advanced, and supposedly benevolent, group like SF to try to help species. The Federation does not run on the rules of natural selection or fate, they don't go with survival of the fittest. I get the reasons for the prime directive, and it can be a good guideline. but, thats what it should be, a guideline. Its not Star Fleet's religous text. It is not infallible. Even then, I'd argue the people after kirk interpret it in a way that is much more restricting then they should. not giving a culture tech or talking to them unitl they're ready is fine, but letting them die, especially of external events, because revealing yourself, or like in "Homeworld" even just risking revealing yourself, is a fate worse than death isn't just stupid, its downright immoral. Heck, even the Watcher in the Marvel comic universe (an alien with much stricter rules about noninterference) broke his race's rules and got involved a few times to save Earth. Good thing he wasn't a Starfleet officer, or Earth would be destroyed.
Wow, that was a big post. I needed to get my frustrated with how the PD is sometimes used out of my system