China views Russia as a necessary partner in challenging the global order dominated by the United States. But Mr. Putin’s appetite for risk — seen in his invasion of Ukraine and his reliance on private armies — has forced Beijing to defend its bond with Russia in the face of Western pressure.

Mr. Xi’s long-term bet will work only if Mr. Putin remains in control to help uphold the shared interests of both countries. But the revolt has raised questions about Mr. Putin’s authority: Wagner soldiers faced little to no resistance from regular Russian forces as they advanced on Moscow. And Mr. Putin’s decision to grant sanctuary in Belarus to Yevgeny V. Prigozhin, the leader of the uprising, smacked of a compromise rather than the act of a strongman with consolidated power.

“It makes China realize that the Putin government’s internal politics are actually quite fragile,” said Xiao Bin, a researcher for the Institute of Russian, East European and Central Asian Studies at the Chinese Academy of Social Sciences. “The fragility existed before, but it has increased ever since the start of the Russia-Ukraine war.”