Complete Monster: In the novels A Time to Kill & A Time to Heal, by David Mack, Prime Minister Kinchawn is the leader of Tezwa, a minor planet on the border of the Federation and the Klingon Empire. During the Dominion War, the President of the Federation provided Kinchawn with a secret array of nadion-pulse cannons, to be used against Dominion forces if they ever invaded. Years later, Kinchawn plans to turn Tezwa into a military dictatorship and an empire. Kinchawn declares plans to annex a nearby Klingon planet. The Klingons are enraged, but the Federation convinces them to seek a diplomatic solution. Kinchawn invites the Klingons and the Federation to Tezwa to discuss the matter. The Enterprise and 10 Klingon ships are in orbit of Tezwa, with Picard, Troi and a Klingon representation meeting with Kinchawn on the planet. Kinchawn refuses to apologize and tries to have the 3 of them arrested, killing the Klingon representative in the process. Kinchawn then uses the cannons to attack the ships in orbit, killing 6,000 Klingon warriors. The Klingons counterattack, killing millions on Tezwa. Kinchawn's outrages prompt the Klingons to send an invasion force to conquer Tezwa, that would result in more deaths. After Enterprise manages to disable both the Klingon and Tezwa military fleets and take control of the cannons, the Federation take control of Tezwa and begin a rebuilding and peacekeeping mission. Kinchawn goes into exile and becomes a terrorist, having his supporters engage in terrorist acts against Federation personal on the planet. Worse still, Kinchawn is attacking population centers belonging to the trinae, a racial minority on Tezwa, attempting to commit genocide against them. Eventually, Kinchawn is defeated, but his terrorist campaign ends up killing thousands of Federation personal and Tezwan civilians.
Picard: You know, the last time Beverly took over Starfleet Medical, I was given a stubborn, acerbic, cantankerous replacement who I firmly believed was sent specifically to drive me mad. And I'd love to have her back, if she's interested.
Moral Event Horizon: Prime Minister Kinchawn crosses it rather early, after he uses his illegally-acquired weapons (see: Government Conspiracy, above) to shoot down 10 Klingon ships in orbit of Tezwa, killing 6,000 warriors. If this didn't represent his crossing the line, his casual willingness to see millions of Tezwans killed in a Klingon counterstrike, including his own family, certainly does. What makes it worse is his apparent self-image as a Well-Intentioned Extremist, when he's really totally Drunk with Power. He sees his own children's death as merely a means to acquire more sympathy and thus more support and power, and seems to truly believe this is somehow reasonable.