New Delhi, May 19 -- There was a telling moment on the second day of Donald Trump's visit to Beijing. America's president was strolling with Xi Jinping through the gardens of Zhongnanhai, the Chinese leadership compound, on May 15th. Mr Trump stopped to ask China's president if he often brought foreign leaders there. "Very rarely," said Mr Xi, shaking his head for emphasis. "For example, Putin has been here," he added, with a chuckle. Less than 24 hours later came the announcement that Vladimir Putin, Russia's leader, would follow in Mr Trump's footsteps with a visit to Beijing on May 19th and 20th.

The timing of Mr Putin's visit sends an unmistakable signal. Mr Xi is making it clear that even if he can stabilise relations with America, ...