Xi’s itinerary has not been chosen by chance. Russia’s invasion of its western neighbor and the motivations laid out in Putin’s disquieting pre-attack speech — a rambling intervention that dismissed Ukraine’s right to exist and post-Soviet reality — sent a shudder through the region sitting to its south, where there are significant ethnic Russian minorities. Not only that, but Moscow’s unimpressive and ill-disciplined military performance has been duly noted by nations for whom the country is supposed to act as a security guarantor. Central Asia’s red lines are being redrawn, its spheres of influence recast. China isn’t about to sit...