Han pushed for a two-state solution to the "Palestinian question" during his UNGA remarks, a comment widely read as an implicit jab at the United States and Israel. Xi's absence came just after his high-profile summit with President Trump, a pairing that caught the attention of China watchers in Washington.

Bonnie Glaser, managing director of the German Marshall Fund of the United States, said Chinese officials had signaled months earlier that Xi would only show up at the UN for a major anniversary. His no-show this year fits that pattern.

Beijing is weighing its relationships carefully. China still wants to present itself as a champion of multilateralism and a rising voice on global issues like the Israeli-Palestinian conflict, but sending a vice-president instead of the president, right after a Trump meeting, suggests Xi and his advisers are putting more weight on the direct line to Washington than on the UN stage.

So the question becomes whether Xi shows up next year, and what anniversary, if any, would be worth the trip.