When Mr Obama visits Asia, he does so as head of state of a battered superpower. No better symptom of US frailty can be found than the dollar – the currency in which Asians have invested so much of their people's hard-earned wealth. But Mr Obama can only grin and ask his hosts to bear it. He does not have the means to rescue the US dollar, on his own.

No better symptom of aversion to the US currency – managed by a central bank determined to blow new bubbles, critics complain – can apparently be found than the jump in the dollar price of gold. This is up 56 per cent over the past year, driven, in part, by fears of Asians over their financial future.

Over the same 12 months, the Federal Reserve's broad, trade-weighted, nominal exchange rate index has lost only 8 per cent of its value. It is still 8 per cent higher than in July 2008, before the flight to the safe haven of the dollar triggered by the post-Lehman crisis. Thus, the huge jump in the price of gold suggests a flight from currencies, in general, rather than one from the dollar, in particular.