As it was in the past, the main function of the UN today is to maintain peace and security for all of its member states. Though the UN does not maintain its own military, it does have peacekeeping forces which are supplied by its member states. On approval of the UN Security Council, these peacekeepers are often sent to regions where armed conflict has recently ended to discourage combatants from resuming fighting. In 1988, the peacekeeping force won a Nobel Peace Prize for its actions. In addition to maintaining peace, the UN aims to protect human rights and provide humanitarian assistance when needed. In 1948, the General Assembly adopted the Universal Declaration of Human Rights as a standard for its human rights operations. The UN currently provides technical assistance in elections, helps to improve judicial structures and draft constitutions, trains human rights officials, and provides food, drinking water, shelter, and other humanitarian services to peoples displaced by famine, war, and natural disaster. Finally, the UN plays an integral part in social and economic development through its UN Development Program. This is the largest source of technical grant assistance in the world. In addition, the World Health Organization, UNAIDS, The Global Fund to Fight AIDS, Tuberculosis, and Malaria, the UN Population Fund, and the World Bank Group to name a few play an essential role in this aspect of the UN as well. The UN also annually publishes the Human Development Index to rank countries in terms of poverty, literacy, education, and life expectancy.