According "The Undiscovered Country", "70 years of unremitting hostility with the Klingons" were about to come to an end. So that would put a potential Klingon conflict 20 years prior to Donatu-5 if TUC occurred in the mid-2290s.
Just so we're clear, the hostilities started 20 years prior to Donatu V and continued up until TUC, correct? So Donatu V would have been part of that hostile period, since "unremitting" means "never slackening or stopping; unceasing; constant". Which doesn't take into account the enforced peace of the Organian Peace Treaty in 2267, of course ;-/
I find it hard to beleive that the Federation was in a constant state of war for 70 years, since the Enterprise, the pride of Starfleet, saw relatively little action against the Klingons. so I guess the idea of the Cold War with various flareups makes the most sense.
Well even during the Organian Peace Treaty the Klingons were still...
- Poisoning grain supplies ("Trouble with Tribbles")
- Sabotaging the Enterprise's warp engines to make it look like an accident and then decided to just outright attack the ship. ("Elaan of Troyius")
- Sneaking across the neutral zone to destroy the Grissom and attack the Enterprise ("The Search for Spock"). (When did the Organian treaty end anyway?
)
And that's the incidents that we're aware of...
From the Federation's POV, it probably was "unremitting" and "hostile"...
