Star Trek: All Good Things - Reality Vs Fiction
9. The Khitomer Accords
What Happened In The Episode: All Good Things's future shows that the Khitomer Accords have been suspended, with the Federation and Klingon Empire now in a state of cold combat. Going back to Star Trek VI: The Undiscovered Country, the Klingon Empire was a stand-in for the USSR, with the explosion of Praxis a Trek take on the accident at Chernobyl. All Good Things also introduced the Neagh'var-class attack cruisers that attack the USS Pasteur. Though they are overpowered by the Galaxy-class Enterprise-D, they still manage to deliver a devastating attack on the hospital ship.
What Really Happened: In Star Trek: Deep Space Nine's fourth season, the studio mandated that the approaching Dominion War had to be slowed down. Therefore, the Klingons were brought back as antagonists. As Ira Stephen Behr described it, this was the season where 'the Klingons went crazy'. The second episode of that season, The Visitor, showed a future with Starfleet and the Klingons still in a state of cold war.
The Way of the Warrior brought Neagh'var Class ship into 'modern' continuity as well, further suggesting that the future shown here would come to pass.
The Klingons have yet to appear in Star Trek: Picard, so it remains to be seen which direction they will be taken in. However, all evidence suggests they will not be the allies they once were.