Thirty years ago, U.N. Secretary-General Boutros Boutros-Ghali offered an ambitious vision of the institution he led. The Cold War was over. Globalization was drawing countries together even as fragmentation threatened to pull them apart. The United Nations, he argued, could help build a more cooperative international order.

He was remarkably confident. Nations would be bound closer together, and the credibility of the U.N. would deepen “year by year.”