The leaders at India’s showpiece G20 Summit arrived at a joint communique — called the G20 New Delhi Leaders’ Declaration — after months of work and, in the last stretch, five sleepless nights of negotiations. The big sticking point was the Ukraine-Russia conflict, which was addressed in detail in seven paragraphs. This is much more elaborate than the Bali Declaration, which had just two paragraphs. The consensus at the Bali declaration frayed and broke down within a month of the Summit in November last year, and the last nine months witnessed acrimony on both sides — the G7 grouping on...