Today, Native American tribes are divided into two categories: those recognized by the federal government, and those not formally "recognized" by the United States. Tribes that are federally recognized receive the benefits and services exclusively reserved by the federal government for those classified as Indians. As a result of historical circumstances, nonrecognized tribes are excluded from federal assistance because they have not maintained a formal relationship with the United States. Denied their status as "Indians," members of nonrecognized tribes have sought the assistance of the federal judiciary to compel the federal government to comply with its trust obligations to all Native Americans. Courts have struggled to decide "whether and to what extent old promises should be honored" to Indian tribes, (4) a question made more difficult when considered as to tribes not recognized by the federal government.