New Delhi, June 3 -- FOR THE better part of a decade China has repeated the same message to foreigners: unlike certain unmentioned countries pushing for unilateralism and protectionism, China is a force for stability and certainty. At times this can be a hard sell. But as the globe lurches from the lunacy of Donald Trump's tariffs to the fallout from his attacks on Iran, Chinese officials are making their pitch to an audience that needs little persuading-and they know it. Business executives and diplomats who have recently met Chinese leaders report that they seem supremely confident.

This has made for extreme claims about the impact of the Iran war on China's economic standing. In the immediate aftermath of the bombing, some of Mr Trump...