For Guy Debelle, it was the two years he rarely slept – spending much of the time on the phone to panicked bankers overseas and flying back and forth between Australia and Europe.

Within months of Debelle becoming assistant governor for financial markets at the Reserve Bank of Australia in 2007, US investment bank Bear Stearns’ hedge funds faltered. Lehman Brothers would fail a year later, in a crisis that took the financial system to the brink of collapse.