… Yet some United Nations insiders speak of a woman far more established on the world stage: Chancellor Angela Merkel of Germany. There was speculation in the German media last year about her possible candidacy, though it subsided and since then she has had her work cut out as Germany welcomed a huge influx of refugees.

With elections in Germany due next year, the newsmagazine Der Spiegel quoted colleagues of Mrs. Merkel’s saying that she does not wish for a fourth term. With Europe’s immigration crisis inciting resistance to her continued open-door policy, there is talk of a “graceful exit” for the chancellor.

No candidate could magically restore the United Nations’ prestige, but there is a compelling logic in favor of a Merkel candidacy. She is both female and, as someone who grew up in the former German Democratic Republic, Eastern European. More important, she has an intuitive understanding of Russia’s president, Vladimir V. Putin, who was based in Dresden as a K.G.B. officer when the Berlin Wall came down. While Russia’s annexation of Crimea sorely tested Mrs. Merkel’s patience, she continued to have regular telephone conversations with Mr. Putin. She could bring a unique ability to mediate between Russia and America.

Germany’s remarkable response under her leadership to Europe’s refugee crisis has also underlined Mrs. Merkel’s humanitarian credentials. At the eight of last year’s wave of migration, the contrast between Mrs. Merkel’s willingness to accept desperate asylum seekers in their hundreds of thousands contrasted with the parsimonious response of Britain’s prime minister, David Cameron, as well as with a growing xenophobia among some Eastern European leaders. …

Mark Seddon was a communications aide to the United Nations secretary general from 2014 to 2016.