The world economy is disturbingly close to stall speed. The United Nationshas cut its global growth forecast for this year to 2.8pc, the latest of the multinational bodies to retreat. 

We are not yet in the danger zone but this pace is only slightly above the 2.5pc rate that used to be regarded as a recession for the international system as a whole. 

It leaves a thin safety buffer against any economic shock - most potently if China abandons its crawling dollar peg and resorts to 'beggar-thy-neighbour' policies, transmitting a further deflationary shock across the global economy.