It seems like the Prime Directive is a Starfleet rule but they've definitely come down on folks outside of Starfleet who were interfering with alien worlds, including John Gill, Nikolai Rozhenko, and even the Ferengi running a con in the Delta Quadrant. Kirk armed the tribe in A Private Little War to counter Klingon interference. They don't want it happening at all.
John Gill "Used to Teach at StarFleet Academy".
Spock, who studied
Earth history from a text prepared by Gill, was impressed by his treatment of
history as "
causes and motivations rather than dates and events."
James T. Kirk, who studied under Gill at Starfleet Academy, remembered him as "
the kindest, gentlest man I ever knew." (
TOS: "
Patterns of Force")
There's no way John Gill didn't know about StarFleet's "Prime Directive" if he taught at StarFleet Academy.
His interference severely caused the Planet to change it's course of history.
And he might have "Contract Clauses" from his time teaching History at StarFleet Academy that he violated.
Before Gill died, he admitted to Kirk he was wrong to violate the Prime Directive, and commented on the irony that even historians fail to learn the lessons of history.
That could explain why Kirk & StarFleet felt the need to interfere in this case, to counter the interference by somebody that was formerly related to StarFleet.
Nikolai Rozhenko is also related to StarFleet Academy to some degree, even if he was a drop-out.
Nikolai
attended Starfleet Academy but dropped out after one year because the rules were too stringent.
There might be something in the StarFleet Academy contract that you signed where if you violate the Prime Directive, StarFleet might come after you to either "Prosecute you" or "Clean Up your mess" that you caused should you choose to violate the Prime Directive, even after you leave StarFleet.
ST:VOY.S3.E05 - "False Profits"
As for the 2x Ferengi Swindler's, Janeway felt that StarFleet was Partially Responsible.
Chakotay and Paris report this to the rest of the
Voyager crew, explaining how the Ferengi have used their advanced technology to exploit the
local myth, which foretold that Great Sages were prophesied to come from the sky in a ball of fire. Tuvok has solved the mystery of how the Ferengi arrived in the
Delta Quadrant:
several years earlier, while the
USS Enterprise-D was hosting negotiations for the rights to the
Barzan wormhole (negotiations that collapsed when it was discovered that one of its endpoints wasn't fixed) the two Ferengi,
Arridor and
Kol, who were minor functionaries, became trapped in the Delta Quadrant during an ill-thought out attempt to secure it for themselves.
Janeway decides that they're not going to just leave the innocent Takarians to be used and exploited any longer, feeling that the Federation is partially responsible for what has happened, since they were the ones to have hosted the negotiations in the first place. The plan is to take Arridor and Kol back to the Alpha Quadrant and turn them over to the Ferengi authorities.
That's why Janeway felt the need to interfere & clean up StarFleet's previous mess.
As for Kirk arming the Tyree people in "
A Private Little War", apparently Kirk violated the
Prime Directive earlier when he was scouting on the Planet
Neural.
James T. Kirk visited Neural as a young lieutenant in 2255 and conducted a planetary survey as his first command. During this mission,
he befriended the hill man Tyree and, in a technical violation of the Prime Directive, revealed that he was from another world of more advanced technology.
Tyree swore himself to secrecy and proclaimed Kirk his brother, vowing never to reveal what he knew. Lieutenant Kirk then completed his survey
mission and found the inhabitants to be a peaceful, low-
technology civilization that was
centuries or
millennia from developing any advanced technology.
In
2268, a followup visit revealed that the inhabitants were now divided into warring
factions, with some factions possessing
flintlock firearms that were centuries beyond their level of technology. It was quickly discovered that the
Klingon Empire contacted the planet in 2267 and was tampering with the natives by arming some of the warring factions while giving them gradual weapon improvements to make it appear that the natives were developing them on their own, albeit at a suspiciously accelerated rate. Fearing that the planet could fall to Klingon influence, Kirk decided to violate the Prime Directive and contact opposing factions, helping them to fight the Klingon-backed tribes.
Using an analogy derived from the "
Brush Wars" of the
20th century where
major powers fought their wars through smaller proxies, Kirk set up a Federation-backed faction on Neural by providing flintlocks to the hill people that were the victims of the Klingon-backed aggression.
This Prime Directive Violation seems to be Politically Motivated since there was a "Cold War" with 'The Klingons' at the time.
So Kirk probably got the Approval of Upper Brass to equal things out with "The Klingons" and their proxies since the tampering was irrevocable by "The Klingons" and James T. Kirk already violated the Prime Directive in the past with said planet.
I doubt Kirk ever got punished for this for obvious political reasons since his actions would help the UFP and stymie the Klingons influence on a primative world.
One where the UFP are in a "Cold War" with.
The reason I bring up "Contract Clauses" with StarFleet is that once you are Affliated with "StarFleet", even if you leave the service or employ of, there might be certain rules/regulations that you are bound by for the rest of your life. Similar to how those with "Security Clearance to Classified Information" in the US, they have a
LifeTime Commitment that is required, even if you retire, leave the employ of the US Government.
When a cleared individual leaves the job or employer for which they were granted access to classified information, they are formally debriefed from the program.
Debriefing is an administrative process that accomplishes two main goals: it creates a formal record that the individual no longer has access to the classified information for that program; and
it reminds the individual of their lifetime commitment to protect that information.
Typically, the individual is asked to sign another
non-disclosure agreement (NDA), similar to that which they signed when initially briefed, and this document serves as the formal record. The debriefed individual does not lose their
security clearance; they have only surrendered the need to know for information related to that particular job.
There might be something similar in the "StarFleet Contract" that you sign when you decide to join up with StarFleet or be "Employed by StarFleet" in some capacity.
That they are legally bound to the "Prime Directive", even after leaving the service or stop being Employed by StarFleet.
And this applies to the rest of the persons life as a "Life-Time Commitment".