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. This directive can be found in the Articles of the Federation, which states:

Similar to 0 things you like: