Just when it appeared that tensions between the US and China were easing after the meeting between presidents Donald Trump and Xi Jinping on the sidelines of the Group of 20 summit in Buenos Aires came news of the arrest of Ms Meng Wanzhou, chief financial officer of the Chinese telecom giant Huawei and daughter and putative heir of the company's founder. Ms Meng, 46, was arrested by the Canadian authorities, at the request of the US, while in transit in Vancouver. Her alleged crime is Huawei's suspected move to circumvent US sanctions on Iran through a Hong Kong proxy. Apparently, the US authorities were tipped off, and it appears the arrest was a carefully planned American manoeuvre.

By plucking a person so close to the Chinese Communist Party elite - Ms Meng's father is a former People's Liberation Army officer - the US was possibly sending a message as blunt as the one Mr Trump gave to Mr Xi at their first summit last year, when he told his guest over dinner that 59 Tomahawk missiles were headed to Syria at that very moment. This after China previously made clear it opposed the US taking unilateral action in that long-running conflict. China's angry reaction this time - the Vice-Foreign Minister summoned the Canadian and US ambassadors to protest - suggests it reads Ms Meng's arrest as an attack on its foreign-facing industry, if not the Communist Party itself. China's state media has kept up a strong anti-US line. But a few points to note.