George Osborne has taken a major gamble. The UK chancellor of the exchequer's decision to endorse a half-formed proposal to force banks to separate their UK retail operations from their investment banking arms is a leap in the dark that could have unintended global consequences.

For Osborne, the gamble is good politics. Last year, he rashly handed control of the bank overhaul agenda to an Independent Commission on Banking, leaving himself with little choice but to accept its recommendations or risk a clash with his coalition partners. By adopting its central proposal three months before the commission is due to deliver its final report, Osborne can at least reclaim the initiative, presenting himself as a bold and radical reformer while proclaiming an end to regulatory uncertainty for the banks.