Klingons Stopped Using 1 Trick Against Starfleet After Star Trek 6

Star Trek's Klingons stopped using a particular espionage tactic against the United Federation of Planets after Star Trek VI: The Undiscovered Country. Set in 2293, Star Trek VI ushered in a détente between the Klingon Empire and the Federation after the Klingon moon Praxis exploded. With the Empire on the brink of economic collapse, Klingon Chancellor Gorkon (David Warner) sued for peace with the Federation. Peace was ultimately achieved and lasted well into the 24th century Star Trek: The Next Generation era.

At the height of the 23rd century Cold War between the Klingon Empire and the Federation - which escalated to violence in the Klingon War of 2256-2257 as seen in Star Trek: Discovery - the Klingons developed the means to surgically alter themselves to appear human. Given the stark physiological differences between Klingons and humans, this was a brutal and painful procedure, but at least two known Klingons were subjected to the torture in order to spy on Starfleet and the Federation. However, this practice stopped after Star Trek VI.

Why Klingons Stopped Infiltrating The Federation Disguised As Humans After Star Trek VI

Peace Ended One Particular Klingon Spy Practice

After Star Trek VI: The Undiscovered Country marked a new era of cooperation between the Federation and Klingon Empire, there was no longer any reason for Klingons to surgically alter themselves into humans to become spies. The Klingons became allies of the Federation and openly worked with Starfleet. Lieutenant Worf (Michael Dorn) then became the first Klingon in Starfleet, rising to become Security Chief of the USS Enterprise-D in Star Trek: The Next Generation.

While it's unknown how many Klingons became human spies in the 23rd century, the procedure depicted in Star Trek: Discovery is so torturous that it's likely few Klingon warriors subjected themselves to it. Culturally, Klingons pride themselves on facing enemies in glorious battle, and honorable deaths are seen as a gateway to Sto-vo-kor (Klingon heaven). Besides the indignity of being turned into a human, the process is also apparently irreversible, and this is understandably not welcomed by the Klingons.

Star Trek Has 2 Famous Klingons Disguised As Humans

Star Trek: Discovery, TOS & DS9 Introduced Two Klingon Spies

Star Trek's most infamous Klingon-turned-human is Arne Darvin (Charlie Brill). In Star Trek: The Original Series' classic episode, "The Trouble With Tribbles," Darvin was a Klingon Intelligence operative who was installed as the aide to Federation Undersecretary Nilz Baris (William Schallert). Thanks to Captain James T. Kirk (William Shatner) and crew of the USS Enterprise, Darvin's mission to poison the quadrotriticale grain vital for Sherman's Planet failed when a Tribble exposed Arne as a Klingon.

In the 24th century of Star Trek: Deep Space Nine, Arne Darvin returned and attempted to take revenge on Captain Kirk. Darvin used a Bajoran Orb of Time to travel back to the 23rd century and assassinate Kirk with a bomb he placed inside a Tribble. However, thanks to Captain Benjamin Sisko (Avery Brooks) and the crew of Deep Space Nine, Darvin failed once again and was apprehended.

Star Trek: Discovery not only depicted the gruesome procedure to surgically alter a Klingon into a human, but also introduced its first victim: Voq (Shazad Latif). Voq was physically transformed into a human with the likeness of Starfleet Lieutenant Ash Tyler. Voq/Ash became part of the USS Discovery's crew, but he later joined his love, L'Rell (Mary Chieffo), when she became Chancellor of the Klingon Empire. At the end of Star Trek: Discovery season 2, Starfleet assigned Ash Tyler command of Section 31.

Romulans Infiltrated The Federation Disguised As Vulcans - And Did A Lot More Damage

Commodore Oh Altered The Course Of The Federation

Like the Klingons, the Romulans also used moles to infiltrate Starfleet, but they were able to do significantly more damage and even altered the course of the Federation in the late 24th century. Star Trek: Picard season 1 revealed that the Romulan Tal Shiar sect called the Zhat Vash installed General Nedar (Tamlyn Tomita) as Commodore Oh, who rose to become Starfleet's Head of Security. Oh was aided by Narissa (Peyton List), who performed black ops as assassinations for Starfleet Intelligence as Lieutenant Rizzo.

Commodore Oh posed as a Vulcan, which was far simpler than Klingons being altered into humans, since Romulans are a genetic offshoot of the Vulcan species. Similarly, Narissa could easily become the human Lt. Rizzo with a few minor physical alterations, like rounding out her pointed ears. Captain Kirk in Star Trek: The Original Series and Counselor Deanna Troi (Marina Sirtis) becoming a Romulan in Star Trek: The Next Generation show how relatively easy and painless back-and-forth transformation is.