In July 2007, the then chief executive of Citigroup, Charles Prince, captured the hubris of a market dangerously addicted to debt: "When the music stops, in terms of liquidity, things will be complicated. But as long as music is playing, you have got to get up and dance. We're still dancing." By the end of the year, Mr Prince was forced to resign along with some of the most influential bankers on Wall Street. Global investment houses in the United...