Another week, another series of flip-flops by America’s president. Last week, along with reversing course on Nato, Federal Reserve chair Janet Yellen and the US Export-Import Bank, all of which he is much keener on now than he was a week earlier, Donald Trump did not, after all, designate China a currency manipulator.

For someone who railed against Beijing’s unfair exchange rate practices, excoriated his predecessors for failing to confront the issue and swore he would name China as a manipulator on his first day in office, this was quite a climbdown. As it happens, it is a perfectly sensible move. But given that it was coupled with vainglorious comments about the dollar being too strong because of confidence in him, Mr Trump’s about-turn suggests an enduringly eccentric approach to policymaking more than it does a principled and considered change of mind.

Whatever China has done in the past, the idea that it is intervening to gain a competitive advantage is absurd. Terrified of a vicious circle of a sliding currency and uncontrolled capital flight — of the kind that rocked world markets in August 2015 — Beijing has spent billions of dollars in recent years propping the renminbi up, not pushing it down