Over the past few years, British businesses operating in America have learned the hard way exactly how brutal the US can be when things go wrong. British banks have had to pay billions of dollars in fines to settle investigations by US regulators, ranging from allegations that Barclays rigged LIBOR to claims that Standard Chartered breached US sanctions against Iran. … The US Department of Justice has hardly given JP Morgan an easy ride of late. Last week, America’s biggest bank was fined $5.1 billion, most of which related to wrongdoing at Bear Stearns and Washington Mutual, companies JP Morgan...