The Economist traces the history of tensions between Shi'ites and Sunnis, noting that the Iranian revolution led to unrest amongst Shi'ites in the Arabian Gulf some thirty years ago but that the Sunni rulers of the Arab Gulf countries pacified their minority Shi'ite populations by according them "a few rights and promising them more". Recently, however, with the arrival of the abrasive President Ahmedinejad in Iran, there are signs of growing sensitivity amongst Shi'ite minorities. The recent riot in the Holy City of Madinah illustrates the tensions that exist.
