Last September, as dust and debris from the tellers’ floors began raining onto the empty vaults below, a note of satisfaction was sounded by bankers in the Arab world. Financial institutions sticking to the tenets of Islam, they announced, were largely immune from the debt crisis. Devout Muslims may lend and borrow under certain conditions; they can even buy and sell debt in the form of ‘Islamic’ bonds, but most other kinds of debt trading are frowned on.