Sixteen years after the fateful day the United Nations (UN) charter was promulgated in San Francisco, President John F. Kennedy memorably intoned on a return to that city that the UN “remains mankind’s best hope to conquer war, poverty, and disease.” Across subsequent decades this aspiration has been shared by US presidents from Ronald Reagan, who believed that the UN could help “bring about a new day,” to George H.W. Bush, who recognized the UN system as “poised to historic vision of its founders—a world in which nations recognize the shared responsibility for freedom and justice.”