Now that US President Donald Trump’s tariff war is in full swing, investors around the world are asking: What’s next on his agenda for upending the global economic order? Many are turning their attention to the so-called “Mar-a-Lago Accord” - a plan proposed by Stephen Miran, chair of Trump’s Council of Economic Advisers, to coordinate with America’s trading partners to weaken the dollar.

At the heart of the plan is the notion that the dollar’s status as the world’s reserve currency is not a privilege but a costly burden that has played a major role in the deindustrialisation of the Ame...