The concept of entropy in international relations is instructive here, Rudd writes: “Under this argument, any international order, once established, is immediately subject to the natural processes of decline and decay, ultimately resulting in a return to disorder.”

There is “growing evidence of nation-states walking around the UN to solve major problems and then perhaps coming back to the UN when it’s all done as some sort of diplomatic afterthought,” Rudd told me. The United Nations continues to establish rules for how people and states should conduct themselves in the world. “The problem is, if you simply set norms and don’t do anything about the execution of those norms, as the international agency given that function back under the charter of 1945, then you start to lose complete relevance over time.”

I asked Rudd whether the remaining secretary-general candidates were advocating the kinds of reforms he’d like implemented at the United Nations. “I ... understand that in a competitive selection process such as this, many candidates are going to choose to be publicly diplomatic about the sort of problems the UN faces,” he responded. Presumably he himself can be less diplomatic, now that he is no longer auditioning to be the world’s chief diplomat.

“We are facing the biggest set of external changes and challenges to the global order since 1991,” following the fall of the Soviet Union, Rudd told me. “Over the last 25 years, we haven’t seen anything comparable to the current state of great-power relations. We haven’t seen anything comparable to the current intensity of the globalization process. We haven’t seen anything comparable to the emergence, for example, of terrorism as a mainstream threat to many societies across the world. These are new phenomen[a]. Each age has had its own new phenomenon. But in a quarter of a century, which is a long time [for] an institution that only has a 70-year history, it’s a set of circumstances which should cause us to act.”

Rudd’s report includes numerous prescriptions for reinventing the institution, from striking a new international agreement on resettling refugees to more rigorously measuring the results of UN initiatives. The United Nations, Rudd told me, is much better at reacting to crises than anticipating and preventing them. He proposes investing in a policy-planning staff that can analyze global trends several years into the future, and in what he calls “preventive diplomacy.” As an example, he cited the UN’s appointment in 2013 of the former president of East Timor, Jose Ramos-Horta, as a special representative to the West African nation of Guinea-Bissau, which had just experienced a military coup; within roughly a year, Ramos-Horta had helped forge enough political consensus for elections to be held. Prevention could also mean, for instance, prepositioning food aid in countries at the earliest warnings of famine, or tracking unemployment patterns to predict where violent extremism could emerge.