Star Trek: Strange New Worlds season 2 episode, "Tomorrow and Tomorrow and Tomorrow" subtly references early The Original Series canon.
Star Trek: Strange New Worlds season 2, episode 3, "Tomorrow and Tomorrow and Tomorrow" has a subtle shoutout to Star Trek: The Original Series. When Lt. La'an Noonien-Singh (Christina Chong) and an alternate universe version of Captain James T. Kirk (Paul Wesley) find themselves on 21st-century Earth, they must fight to restore the proper timeline. After encountering a strange intruder on her 24th-century USS Enterprise, La'an ends up on a very different version of her ship. She soon discovers that the timeline has been drastically altered, and neither the Federation nor Starfleet exist as she knew them.
Though the organizations and missions of the Federation and Starfleet have been well-established by this point in Star Trek canon, this was not always the case. When Star Trek: The Original Series began in 1966, the television landscape was much different than it is today. Shows usually did not have complicated mythologies or even stories that lasted for multiple episodes. Many of the episodes of TOS aired in a different order than they were filmed, making it difficult to establish a consistent and logical canon. Though the term Starfleet has become inextricably linked with the Star Trek franchise, that was not the first term used to describe the Federation's organization of ships.
Strange New Worlds' United Earth Fleet Is A Nod To Early Star Trek: TOS
The Captain Kirk introduced in "Tomorrow and Tomorrow and Tomorrow" comes from an alternate timeline where Earth never established the Federation or Starfleet. When La'an Noonien-Singh appears on the alternate USS Enterprise, she learns that the ship serves as a United Earth Fleet vessel in a timeline significantly different from her own. Soon after La'an arrives on the bridge, the Enterprise is contacted by a Vulcan ship commanded by Spock (Ethan Peck) who asks for help in the war with the Romulans. Kirk refuses, claiming he cannot fight a war on two fronts.
In this timeline, Earth and Vulcan never came together to help found the United Federation of Planets, and the galaxy is much worse off because of it. The name United Earth Fleet not only serves to establish that Earth is not a member of the Federation, but also feels reminiscent of the terms TOS tried out before landing on Starfleet. Star Trek: The Original Series largely established what is now considered Star Trek canon as it went along. Because of this, several names were used for the organization that controlled the Enterprise before Starfleet became the officially accepted name.
How Star Trek Decided On The Name Starfleet
Star Trek: The Original Series cycled through many names for their space exploration group before landing on the name Starfleet. Now incorporated into Star Trek canon as a predecessor to Starfleet, one of the first names mentioned was the United Earth Space Probe Agency or UESPA. Various other names were tried out throughout TOS, some clunkier than others. These names included: Space Command, Space Service, Space Central, Star Service, Spacefleet Command, and Galactic Command. The terms Starfleet and Starfleet Command were first used in the season 1 episode "The Menagerie: Part 1," though it would take a few more episodes before the name truly stuck.
Considering the nature of television in the 1960s and the lack of the internet, it's not surprising that it was sometimes difficult to keep track of established canon. Though the creators of Star Trek tried out many different names for their exploratory space organization, once the name Starfleet stuck, it became an essential part of the franchise. As a prequel, Star Trek: Strange New Worlds continues to reimagine and update the established canon, and their United Earth Fleet provides another wink to the earliest days of Star Trek.