Dorvan V

Dorvan V was a class M planet located near the border between the United Federation of Planets and the Cardassian Union. In 2350, a Native American group, whose ancestors had left Earth in the 22nd century in order to preserve their traditional culture, settled on Dorvan V. However, in the Federation-Cardassian Treaty of 2370, the Federation ceded its claims on Dorvan V to Cardassia, and charged the USS Enterprise to evacuate the human colonists. The colonists, however, resisted this forced relocation, nearly leading to a military confrontation. This was avoided when Cardassian Gul Evek agreed to a plan which would allow the humans to remain on Dorvan V, under Cardassian authority. (TNG episode: "Journey's End")

In an alternate timeline, a military confrontation did result over the question of the Dorvan V evacuation, leading to a six-day battle and a renegotiation of the border. (TNG short story: "Gods, Fate, and Fractals")