On the 80th anniversary of the United Nations, an American president stood before the General Assembly of global heads of state and offered a withering critique of the institution he had come to address. Donald Trump did not sketch an end to multilateralism as much as an end to multilateralism with the United States at the center of it. 鈥淭he question now,鈥 Trita Parsi of the Quincy Institute tells the Monitor鈥檚 Howard LaFranchi, 鈥渋s whether the U.N. can retain and even enhance [its] usefulness while maintaining鈥 its role as a 鈥渦seful instrument of management of relations among the great powers.鈥