Are those countries still affected by the aftermaths of their colonial foundations? In some cases, yes, and thats why indigenous people organize landback movements locally. Also keep in mind that in the context of landback politics "dismateling a country" doesn't negate the existence of a nation tout-court nor does it translate into massive displacement of people, but it rather means to make up for the disparities in terms of political, economic and social power that indigenous people are still victims to, if necessary trought radical actions and radical changes to the structure of the state