Six decades after its establishment, the United Nations and its system of related agencies and programs are perpetually in crisis. While the twentieth-century’s world wars gave rise to ground-breaking efforts at international organization in 1919 and 1945, today’s UN is ill-equipped to deal with contemporary challenges to world order. Neither the end of the Cold War nor the aftermath of 9/11 has led to the “next generation” of multilateral institutions. But what exactly is wrong with the UN, and...