Despite many warnings of an imminent attack ever since the global financial crisis, the dog of traditional trade protectionism has stayed in its kennel, emitting only the occasional growl.

Finally, there may be some signs that the hound is stirring. The existing mechanisms that allow a limited amount of protection but essentially keep the beast on a leash still seem, happily, to be working.

This week the World Trade Organisation released its regular report on policy in the Group of 20 large economies. It showed the highest rise in new protectionist measures since the WTO started the monitoring exercise in 2009. On top of a marked slowing of world trade growth relative to the expansion in overall global gross domestic product over the past few years, and the sometimes extreme protectionist rhetoric emanating from the likes of Donald Trump, this is clearly a cause for concern.