In the blue corner sit US Treasury Secretary Tim Geithner and his British counterpart, Alistair Darling, who argue that a revival of the Glass-Steagall Act, which divided investment banking from commercial banking, is not appropriate for today’s markets. They believe that regulators can ring-fence capital supporting different business lines, to prevent contagion risk, and perhaps impose a surcharge on large “systemic” firms, to reflect the price of their implicit support from the central bank and government.