The forthcoming Group of 20 meeting is a make-or-break event. Unless it comes up with practical measures to support the less developed countries, which are even more vulnerable than the developed ones, markets are going to suffer another sinking spell just as they did last month when Tim Geithner, Treasury secretary, failed to produce practical measures to recapitalise the US banking system.

This crisis is different from all the others since the end of the second world war. Previously, the authorities got their act together and prevented the financial system from collapsing. This time, after the failure of Lehman Brothers last September, the system broke down and was put on artificial life support. Among other measures, both Europe and the US in effect guaranteed that no other important financial institution would be allowed to fail.

This necessary step had unintended adverse consequences: many other countries, from eastern Europe to Latin America, Africa and south-east Asia, could not offer similar guarantees. As a result, capital fled from the periphery to the centre. The flight was abetted by national financial authorities at the centre who encouraged banks to repatriate their capital. In the periphery countries, currencies fell, interest rates rose and credit default swap rates soared. When history is written, it will be recorded that – in contrast to the Great Depression – protectionism first prevailed in finance rather than trade.