The humanoid inhabitants of Mordan IV, who endured forty years of civil war fuelled by weapons that a Starfleet negotiator secretly supplied to both sides.
The Mordanites are the people of Mordan IV, seen in the Next Generation episode Too Short a Season. Decades before, the leader Karnas took Federation citizens hostage and demanded weapons. The Starfleet negotiator Mark Jameson gave him what he wanted and then quietly armed his rivals as well, hoping to keep a balance. The result was a civil war that lasted forty years.
In 2364 Karnas, now governor of a planet at peace, reports a new hostage crisis and asks for Jameson by name. The Enterprise brings the elderly admiral, who has been taking an alien rejuvenation drug and grows younger by the hour.
Karnas turns out to be holding the hostages himself in order to take revenge. Faced with a dying young man he hardly recognises, he lets the matter end and releases his prisoners.