Four connections between the treaty-making process, federal policies of Native American removal, and the Doctrine of Discovery are Western colonialism, a belief that Indigenous peoples are racially inferior, the cloaking of dispossession in the language of legality, and the use of law to justify what are fundamentally illegal acts.
The process of dispossessing Native Americans lasted for centuries. At different times, different governments used different strategies to take ancestral lands from Indigenous peoples.
But most of these strategies were based on the idea that government policies towards the native peoples of America were somehow in accordance with the law, or at least the English common law tradition on which American law was based.
All of these phenomena were based on the idea that the common law tradition gave white Americans entitlement to land that had been in the possession of Indigenous people for centuries.
However, once the legalistic language of treaties, legislation authorizing forced Indian removal, and the Doctrine of Discovery are stripped away, what we're left with is a naked land grab by people who believed that their race and culture justified them in taking whatever they wanted from the Indigenous population.
In effect, the law was employed to lend respectability to what was, in fact, a far from respectable endeavor.