For much of the past three years, as it became evident that the US housing bubble was bursting, I believed that the old adage “the US catches a cold, the world catches pneumonia” would be laid to rest, helped by the emergence of the so-called Brics – Brazil, Russia, India, China.

Until September and the collapse of Lehman Brothers, the US investment bank, this was still a reasonable model for the evolving world. However, since mid-September maybe the real question has – unfortunately – become: “What happens if the US itself has caught pneumonia?”