Protectionist dominoes are beginning to tumble across the world

Russia has begun to shut down trade as it adjusts to the shock of Urals oil below $40 a barrel. It has imposed import tariffs of 30pc on cars, 15pc on farm kit, and 95pc on poultry (above quota levels). "It is possible during the financial crisis to support domestic producers by raising customs duties," said Premier Vladimir Putin.

Russia is not alone. India and Vietnam have imposed steel tariffs. Indonesia is resorting to special "licences" to choke off imports.