Re: Double standards?
Do a search on largest banking fines in history (or similar). I think you'll find that the most heavily fined banks were mostly US institutions (eg Bank of America, three entries in the the top ten), and the non-US banks who copped fines in the top ten (HSBC, BNP-P, Deutsche Bank) were done for mostly the same sort of CDO related frauds in the US market. Whereas the big French & German banks got away scott-free with their idiotic lending that burned out the Greek, Spanish and Portugese economies. causing damage that by the time it is past will have lasted a generation (and for which much of the losses still haven't been properly realised and written down).
I'd agree it often looks like foreign corporations get a harsher ride from US regulators - the evidence of the fines appears to show otherwise, and that European regulators give corporations far too much the benefit of the doubt. Whether either approach is more or less successful in discouraging future misbehaviour I can't really say, but the serial mis-selling and related scandals of UK banks in the domestic market don't indicate that the UK approach achieves that.