Antonio Guterres takes the reins of the United Nations on New Year’s Day, promising to be a “bridge-builder” but facing an antagonistic incoming U.S. administration led by Donald Trump who thinks the world body’s 193 member states do nothing except talk and have a good time. The former Portuguese prime minister and U.N. refugee chief says he will engage all governments and show his willingness to cooperate on “the enormous challenges that we’ll be facing together.”