To his admirers, Donald Trump is playing 3- or 4-D chess with such aplomb that they can always identify a considered strategy behind his seemingly baffling foreign policy gambits. Usually, China is the bad guy that the US President is seeking to harm or isolate. Hence, the theory goes that Trump has been pressurising Ukraine for over a year to settle with Russia and give up a large chunk of its cherished sovereign territory in order to drag President Vladimir Putin into America’s friendly orbit – thereby isolating China. Checkmate. Or, in the case of Iran, that Trump decided to...