Even though Dominion was introduced as the villains of the saga. DS9's Runabouts were not only limited in of storytelling, but they would be no match for the Founders' military arm, the Jem'Hadar.
Star Trek: Deep Space Nine's executive producer Ira Steven Behr fought to get a starship, and Paramount and Rick Berman ultimately relented, with the caveat that DS9's ship would have to be smaller than the USS Enterprise or Star Trek: Voyager's ship. Behr also had to change the name he originally wanted, the USS Valiant, because the studio felt a ship starting with the letter "V" was too close to Voyager. But at the start of DS9 season 3, Commander Benjamin Sisko (Avery Brooks) - who finally also became Captain Sisko - unveiled the USS Defiant, an overpowered vessel that was originally designed to battle the Borg. The original Defiant lasted into Star Trek: Deep Space Nine season 7 until the show got a second version of the "tough little ship," and a third version also appeared in DS9 season 6.
DS9's Original Defiant And How It Got A Second One
The original USS Defiant (NX-74205) debuted at the start of Star Trek: Deep Space Nine season 3, "The Search, Part I," and it appeared in 62 episodes of the series. The Defiant helped put DS9 on equal par with Star Trek: The Next Generation and Star Trek: Voyager, and it opened up the show's storytelling possibilities. The Defiant also made its movie debut in Star Trek: First when it was commanded by Worf (Michael Dorn) against the Borg. First originally planned to destroy the Defiant, but DS9's creative team balked, so the "tough little ship" was deemed "adrift, but salvageable" and returned to its home series.
The Defiant was shockingly destroyed by the Breen in Star Trek: Deep Space Nine season 7, episode 20, "The Changing Face of Evil." A casualty of the late stage of the Dominion War, the loss of the Defiant was a serious blow to Captain Sisko and his crew. However, 4 episodes later, DS9 received a second Defiant-class starship, the USS Sao Paulo. The Chief of Starfleet Operations granted a special dispensation for the Sao Paulo to be renamed the USS Defiant, complete with its original call numbers. Back in action, the Defiant led the assault on Cardassia and ultimately helped the United Federation of Planets and its allies win the Dominion War.
Red Squad's USS Valiant Was DS9's Third Defiant
Star Trek: Deep Space Nine debuted another Defiant-class starship in the season 6 episode, "Valiant." Nog (Aron Eisenberg) and Jake Sisko (Cirroc Lofton) found themselves aboard the USS Valiant, which was crewed by the elite Starfleet cadets called Red Squad. At first, Nog wanted to serve alongside the Cadets he ired so much while he was at the Academy, but he and Jake soon realized Red Squad's desire to prove their mettle was a liability that would ultimately lead to their destruction. Sure enough, Red Squad made the fatal error to battle the Jem'Hadar instead of returning home to Earth. The Valiant was destroyed and nearly all hands were lost, but Jake and Nog survived to be rescued by Star Trek: Deep Space Nine's real Defiant.