Possession is nine tenths of the law.
The Black Hills (a small mountain range) were ceded to the Sioux by treaty. We were all well and good with it until gold was discovered there. Then the US government stepped in, claimed the Black Hills, and forced out the Sioux (the descendants of the survivors live on the Pine Ridge Reservation southeast of the Black Hills, a stretch of land "worthless" for agriculture or valuable natural resources).
Because power, not righteousness, is the true path to victory.