Forty-five years ago this month, Pope John XXIII published his ground-breaking encyclical Pacem in Terris (Peace on Earth), arguing that world peace depended on respect for and promotion of human rights. On Friday, April 18, just a week after the Pacem in Terris anniversary, Pope Benedict XVI addressed the United Nations General Assembly making the same argument, but giving added emphasis to the responsibility of the U.N. to uphold human rights even if it means overriding national sovereignty. More frequently referred to in American circles as "humanitarian intervention", the duty to protect, Benedict told the assembly "was implicit in the founding of the United Nations, and in fact, it increasingly characterizes its activity." Drawing on John XXIII’s teaching that the failure of a government to protect its people against violation of their rights or which itself violates them is illegitimate (PT 51), Benedict proposed that intervention by the international community to re-establish the rights of a population are neither "unjustified coercion" nor "a limitation on sovereignty." A major function of the alliance of weak and strong nations in the U.N. system, Benedict contended, is that in a time of crisis the strong come to the aid of the weak in the spirit of solidarity. He referred particularly to "certain African countries" and others adversely affected by globalization. One naturally thinks of Sudan and Congo, where international intervention has been ineffectual due to a lack of both resources and political will, to Zimbabwe where a predatory dictator has reduced a whole population to penury while neighboring countries have failed to challenge him, and to Haiti, Bangladesh and Mexico, among others, where skyrocketing food prices are driving many people into hunger. In linking "the duty to protect" so closely with the purpose of the United Nations and other international organizations, Pope Benedict has made the most explicit statement yet of any pope in favor of strengthening the capacities of the United Nations, and he has offered a very strong challenge to all governments, particularly members of the Security Council and emerging powers like India and Brazil, to take action to protect the rights of the victims of war, predatory government, economic inequality and natural disaster. Given the nationalistic and sometimes xenophobic character of current political debate in the United States, Benedict offers Catholics an extraordinary thesis with which to confront this year’s presidential candidates. Precisely because it contests the conventional wisdom, "the duty to protect" is a topic to be pressed in every available forum. Drew Christiansen, S.J.