In the fictional universe of Star Trek, the Prime Directive, Starfleet's General Order #1, is the most prominent guiding principle of the United Federation of Planets. The Prime Directive dictates that there can be no interference with the internal affairs of other civilizations, consistent with the historical real world concept of Westphalian sovereignty. It has special implications, however, for civilizations that have not yet developed the technology for interstellar spaceflight ("pre-warp"), since no primitive culture can be given or exposed to any information regarding advanced technology or the existence of extraplanetary civilizations, lest this exposure alter the natural development of the civilization. Although this was the only application stated by Captain Kirk in "Return of the Archons", by the 24th Century, it had been indicated to include purposeful efforts to improve or change in any way the natural course of such a society, even if that change is well-intentioned and kept completely secret.
"Pre-warp" is defined as any culture which has not yet attained warp drive technology. Starfleet allows scientific missions to investigate and secretly move amongst pre-warp civilizations as long as no advanced technology is left behind, and there is no interference with events or no revelation of their identity. This can usually be accomplished with hidden observation posts, but Federation personnel may disguise themselves as local sentient life and interact with them.
"No identification of self or mission. No interference with the social development of said planet. No references to space or the fact that there are other worlds or civilizations."Whether this was the full text of the Directive is unclear, but by the Star Trek: Voyager episode "Infinite Regress", which is set in 2375, it is revealed that the Directive has 47 sub-orders.
The non-interference directive seems to have originated with the Vulcans. In Star Trek: First Contact, it is stated that but for Zefram Cochrane's historic warp flight, a passing Vulcan ship would have deemed Earth unready for contact and ignored the planet. However, the policy was not implemented immediately, and did not exist on pre-Federation Earth: in the Enterprise episode "Civilization", Tucker notes that the prohibition is a Vulcan policy, not human. The Prime Directive was not actually written into law until some years after the formation of the Federation — in the original series episode "A Piece of the Action", an early Federation ship, the Horizon, visits a primitive planet and leaves behind several items which alter the planet's culture significantly (most notably the book Chicago Mobs Of The Twenties, which the inhabitants quickly seized upon as a blueprint for their entire society).
An alternative origin comes from the Enterprise episode "Observer Effect," where it is revealed that the Organians also adhere to a form of the Prime Directive. However, as Starfleet does not officially make first contact with the Organians until the original series episode "Errand of Mercy," it is unknown what impact, if any, they had on the development of the directive.
In real life, the creation of the Prime Directive is generally credited to Gene L. Coon, although there is some contention as to whether science fiction writer Theodore Sturgeon, who wrote of the Prime Directive in an unused script for the original series, actually came up with it first. (In fact, the Prime Directive appears fully-formed as much as two decades earlier in Robert A. Heinlein's 1948 novel Space Cadet, which describes a military organization very similar to Star Trek's Starfleet). The Prime Directive closely mirrors the zoo hypothesis explanation for the Fermi paradox. In an interview with Gene Roddenberry in a 1991 edition of 'The Humanist' magazine, he implied it also had its roots in his belief that Christian Missionaries were interfering with other cultures.
In the fictional storyline, the Prime Directive was created by Starfleet and the United Federation of Planets shortly after they were first formed. Since then the Prime Directive has been broken on many occasions, intentionally and unintentionally. Sometimes when a Federation starship or vessel crashes on a planet that has a pre-warp civilization, the survivors or the wreckage are collected by the natives, and this then influences their society, especially when Federation technology is recovered and added to the technology of the planet. Sometimes the Directive is deliberately violated. Circa stardate 2534.0 (2266), in the Original Series episode "Patterns of Force", cultural observer and historian John Gill openly created a regime based on Nazi Germany on a primitive planet in a misguided effort to create a society which combined what he viewed as the high efficiency of a fascist dictatorship with a more benign philosophy. However, the intervention proved disastrous with the regime adopting the same racial supremacist and genocidal ideologies of the original.
By the time of the era of Star Trek: The Next Generation, the Prime Directive was indicated to apply not only to just pre-warp civilizations, but to any culture with whom Starfleet comes into contact. In such situations, the Prime Directive forbids any involvement with a civilization without the expressed consent or invitation of the lawful leaders of that society, and absolutely forbids any involvement whatsoever in the internal politics of a civilization. This understanding of the Prime Directive resembles the concept of Westphalian sovereignty in political science.
For example, in the Star Trek: The Next Generation episode "Redemption," when the Klingon Empire experienced a brief civil war, and Captain Picard refused Chancellor Gowron's request of aid, even though he was the legitimate ruler of the Empire, and even though the Romulans were suspected of supplying weapons to the opposing side, as a planetary civil war was deemed an internal conflict. Although the Prime Directive was not explicitly mentioned, it is presumable that this was the pertinent basis for Picard's refusal, in light of a later example on Star Trek: Deep Space Nine, when the provisional government of the planet Bajor experienced a power struggle that nearly led to civil war. During this conflict, Deep Space Nine Commander Ben Sisko's superior explicitly cited the Prime Directive, and ordered him to evacuate all Starfleet personnel from the station, as the situation was deemed internal to Bajor, even though it was known that the Cardassians were supplying weapons to one side.
Around 20 minutes into the season 2 Next Generation episode 15 Pen Pals, the senior staff has a philosophical discussion regarding the Prime Directive. Troi and LaForge argue that if there is a “cosmic plan” that the presence of the Enterprise and its crew is also to be included in that plan and that that alone allows them legitimate claim to act in behalf of a people in need. Captain Picard argues that one's personal certitude is not relevant and that the Prime Directive is meant to prevent “us” from letting our emotions overwhelm our judgment. This conversation reveals many personal interpretations, by senior officers, of the Prime Directive. Ultimately Dr. Pulaski states that the subject of that episode must be allowed to be the person they were meant to be as she conducted a memory wipe.
On Star Trek: Voyager, the Prime Directive was used more than once as a plot device as well, and on more than one occasion, Captain Janeway also applied the Prime Directive to a situation which clearly did not involve a pre-warp civilization. ("State of Flux," "Maneuvers") Also, in at least two different episodes in which they encountered civilizations that had technology which could shorten their journey home, "Prime Factors" and "Future's End, Part II", policies similar to the Prime Directive was cited as a basis for denying Janeway and her crew access to it. In the episode "Infinite Regress," Naomi Wildman reveals that there are 47 sub-orders of the Prime Directive.
The Prime Directive is known to be superseded by only one other directive, the Omega Directive.
In at least one case (TOS episode 'A Private Little War'), where two different factions of one race were at war with each other, the Prime Directive had been interpreted to mean that neither side could have an advantage, that there had to be a balance of power. With this race, when it was found that Klingons were furnishing one portion of the race with advanced weapons, Kirk responded by arming the other faction with the same weapons. This resulted in an arms race on that world, and was seen as a fictionalized parallel to the then-current Cold War arms race, in which the United States often armed one side of a dispute and the Soviet Union armed the other. A similar arms race served as the backstory of the TNG episode "Too Short a Season." Conversely, Voyager Captain Janeway refused to allow the Kazon-Nistrim and the Kazon-Ogla to have replicator technology, believing it would tip the balance of power among the Kazon factions. ("State of Flux").
On a planet that had two indigenous sentient species, the more advanced one was suffering from a degenerative genetic disorder. A cure was not pursued because it was determined that the more advanced species was genetically stagnant, and that the lesser one was genetically progressive. It was viewed as contrary to nature to help the dying race. Despite the fact that this event took place in the series Star Trek: Enterprise, before the formation of both the Federation and the Prime Directive, it reflects the views of space-faring humans and their allies in the years leading up to the creation of the Federation (ENT episode "Dear Doctor").
In another case, a starship stood by and watched as the loss of a planet's atmosphere was about to wipe out the last remaining members of a primitive civilization, rather than interfere to save their lives. However, the Federation observer refused to stand by, and violated the Prime Directive by saving a small group of that civilization.
There are different conclusions as to the purpose of non-interference. One is that the ends do not justify the means. No matter how well-intentioned, stepping in and effecting change could have disastrous consequences. Another conclusion (strongly implied in the ENT episode "Dear Doctor") is a belief that evolution has a "plan" of sorts, driving species toward purposes. Interference would therefore be unnatural, in that it would go against what is supposed to happen to the species in question.
Some characters have viewed the Prime Directive as a negative policy, because it prevents introduction of technology (especially medical technology), culture, and resources that may improve quality of life. It also has been considered an attitude of moral cowardice by critics of the Federation — that the Prime Directive gives the Federation an excuse not to act. During the brutal Cardassian occupation of Bajor in the early 24th century, the Federation refused to act on the grounds that the occupation was an internal matter of the Cardassian government and to help the Bajorans would violate the Prime Directive. Many Bajorans resented the Federation for years after the occupation because of this attitude. Those in favor of the Prime Directive have said that no one has the right to impose their own standards on others and it is hardly moral cowardice to keep to a difficult, but ultimately beneficial principle in the face of temptation.
Admiral Dougherty's reasons for violation of the Prime Directive in Star Trek: Insurrection in Picard's time echoes the reasons given by Tracy to Kirk in "The Omega Glory" and Picard considers them just as invalid as Kirk did a generation before. In "Homeward" Rozhenko uses holodeck technology to save the Boraalan enforce what he believes is the spirit of the Prime Directive even though Picard has already said such actions violate what it actually states. In "Pen Pals", Captain Picard rectifies contact with an inhabitant of a pre-warp planet by ordering her memory wiped. When contamination became too serious to be fixed by memory wipes, Captain Picard decided to make direct contact with a civilization's leaders in "Who Watches the Watchers" and "First Contact", although the latter episode involved a planet on the verge of achieving warp flight, and therefore eligible for First Contact. Finally, in "Natural Law", the Voyager crew took measures to ensure the protected isolation of a primitive people, even from a more advanced civilization who share the same planet.
In contrast, the Next Generation episode "Justice" did not explicitly explain whether the Edo people were pre-warp or were aware of offworld space travelers prior to the Enterprise's visit. If the case is the former, then when Wesley Crusher is sentenced to death, the violation of the Prime Directive had already occurred and the issue of rescuing him, while politically exacerbating matters, might not have been a violation of the Directive.
There are two special cases in which the Prime Directive does not apply: General Order 24, in which a captain for whatever reason has to destroy an entire inhabited planet's surface, and the Omega Directive, in which a captain is authorized to take any means to destroy Omega Particles when detected.
While no prosecution for a violation of the Prime Directive was ever seen in a Star Trek episode or film, Picard's nine documented violations are held as evidence against him during a witchhunt investigation in "The Drumhead". Additionally, the non-canonical novel Prime Directive, by Judith and Garfield Reeves-Stevens, deals with the political and career fallout from a violation allegedly committed by Kirk. In canon, Captain Kirk apprehended Captain Tracey of the USS Exeter when he found evidence of the latter's apparent violation of the Prime Directive. However, the aftermath of the arrest is unknown.
As 31st Century time traveler Daniels revealed to Captain Jonathan Archer in the Star Trek: Enterprise episode "Cold Front", as time travel technology became practical, the Temporal Accords were established sometime significantly prior to the 31st Century, in order to allow the use of time travel for the purposes of studying history, while prohibiting the use of it to alter history. Some factions rejected the Accords, leading to the Temporal Cold War that served as a recurring storyline during the first three seasons of that series.