“A lot of the juice is outside the United Nations,” said Bruce Jones, the director of the Center on International Cooperation at New York University. “The old days when the U.S. and the Europeans could stitch things up at the United Nations are over, and we haven’t yet seen the emergence of a new platform for action or a consortium for action at the U.N.”

Jones noted that the growing assertiveness of emerging powers – particularly China – has made it harder to reach international compromise. But the United Nations has been hobbled by failures, and distractions, of its own making.

The outgoing head of an anti-corruption office delivered a parting shot to Secretary General Ban Ki-moon in July, accusing him of leading the United Nations into an era of decline. More recently, the top Chinese official at the United Nations, in an alcohol-fueled outburst, noted at a U.N. retreat that he had never really liked Americans, or his boss, Ban.