The US and UK both allowed or encouraged excess credit up to 2007. Both slammed on the brakes too abruptly in 2007-8 and failed to see the impact of their actions on the general economy and the solvency of the banks.
Thereafter, they diverged. The US offered short term financial help, and has now succeeded in gaining full repayment with interest. The UK government chose to own two large banks. They sit at the taxpayers expense, with their share prices well below the price the government paid. As reported here, the US actions were the more sensible.
Owning the banks means it would be even dafter for the UK to impose the kind of levy the President is now inventing – it would be taxing ourselves, and lowering the value of the government’s shares further. UK taxpayers will have to pay Obama’s levy in part – because we own US banks through our ownership of RBS and LLoyds. What a pity they did not got on with selling those overseas banks off earlier, as recommended on this site.