This paper argues that tribes and scholars need to come to grips with the trade-off between trust and self-determination, and that failure to do so-by for example expressing a yearning that the trust doctrine was stronger-will lead to poor choices by tribes. Choices thus need to be based on an understanding of this trade-off and tribes must be aware that exercising self-determination inevitably will lead to a weakening of the trust doctrine over the areas which tribe's assume authority. This point is illustrated using a close analysis of the arguments used by the parties and the Supreme Court's treatment of two Indian Trust Doctrine cases - Navajo Nation and White Mountain Apache. While predictably the scholarship has generally emphasized the Court's failure to fully enforce the trust relationship, this paper's suggestion is that, given the Court's treatment of tribal choices, tribe's must fully understand that exercising their sovereignty in certain spheres can lower enforceable U.S. trust duties. This modest idea - that tribes will be held responsible for their decisions by the courts and therefore need to be deliberate in their exercise of self-determination in particular cases where earlier such cases were controlled by the US government - is actually rather radical in Indian law and as such is likely to open unexplored scholarship and to be significant for tribal leaders.