"The federal trust responsibility, one of the most important doctrines in federal Indian law, derives from the treaties between tribal nations and the U.S. government and from traditional European legal theory. It is the obligation of the federal government —all branches and agencies—to protect tribal self-governance, tribal lands, assets, resources, and treaty rights, and to carry out the directions of federal statutes and court cases. The Supreme Court has defined this" (National Congress of American Indians)