[Dr. Sivana]

You cannot void a treaty between nations.

The entity can voluntary cede it. For instance, Spain and Portugal gave up its claims to most of the Western Hemisphere stemming from "Treaty of Tordesillas".

The Brits did a pretty good (that is botched) job of it when they turned Hong Kong over to the Chicoms, rather than to the Republic of China (Taiwan) with whom the original lease was signed.

The U.S. treaties over Panama were superseded by Jimmy Carter's giveaway.

[BereanBrain]

The Indians are finally getting their treaties honored.