Very few of us remember globalisation in retreat: the last great wave of globalisation swelled in the late 19th century and broke spectacularly with the onset of the first world war. After a rash of protectionism, the great depression and the second world war, the process of expanding trade (and cross-border investment and the flow of ideas and of people) resumed and has continued ever since.

Some economists now wonder if the current wave might also be about to break. The problem is not so much the rolling farce of the Doha round of trade talks, or protectionism in the US - although neither is helpful - but what the price of oil is doing to the cost of shipping goods around the globe. While oil prices have fallen in the past couple of months, they could hardly be described as low. Shipping costs may rise yet further if, as expected, the International Maritime Organisation bans the use of cheaper, dirtier fuel oils by container ships.

There is some anecdotal evidence that this is having an impact on trade: for example, some container ships are reported to be slowing down to save fuel. But there is no sign anything is amiss in the latest World Trade Organization statistics - which, admittedly, date back to 2006. The volume of merchandise trade defied high and rising oil prices to grow at more than 6 per cent a year in 2004, 2005 and 2006.