For Starfleet the war had been a trial by fire against a superior opponent with difficult lessons. The front-heavy armaments which had been increasingly favoured for starships of all types had shown serious weaknesses against more maneuverable Klingon craft, and much of the war had turned on the question of strategic range and speed. Had the fleet been operating at a higher warp factor then lines of defense and strongpoints could have been established much further forward and the loss of Arcadia could have been prevented entirely.
That said, the usefulness of the high-cost and high-performance Excalibur-class could not be overstated. The war had thoroughly discredited a once-popular viewpoint that the future was to be found in light cruisers which could be inexpensively built to carry out the myriad of duties needed in the ever-expanding Federation and then consolidated in the event of warfare. While there was still a place for specialist vessels, military theory in the coming years would be more focused on how to deal with the long-range deployments and individual engagements necessitated by deep interstellar warfare.
With such heavy considerations and indeed such heavy costs, it was a much-needed dose of sunshine when the Attenborough launched shortly after the conclusion of the treaty, a ship very much designed for the ideals that so much blood had been shed to defend. With the end of darkness came the dawn, and an admittedly tattered but resolute Federation emerged from the conflict determined that never again would it be pushed to the brink of destruction.