American exceptionalism, when it runs rampant, is a tsunami to be avoided. The oil company BP is discovering that right now. The environmental disaster destroying seaside communities around the Gulf of Mexico and killing off marine life is a globally important tragedy. BP has to take its sizeable share of the blame. So, presumably, should the American companies like Transocean and Halliburton, which were part of this doomed enterprise. But their nationality seems to have let them off the hook.

As everyone knows, BP is enveloped in a massive environmental and PR disaster, which is doing serious damage to its reputation, not only in the US but across the world. But by relentlessly kicking the firm while it’s down, in what appears to be increasingly brutal and vindictive fashion, the Obama White House is generating significant animosity in a nation that is traditionally pro-American.

Nick Clegg today warned that a row between Britain and the US over the BP oil spill in the Gulf of Mexico was in danger of turning into a destructive bout of "megaphone diplomacy".

The Gulf of Mexico oil spill risked turning into a trans-Atlantic diplomatic rift Thursday after U.S. threats to have BP fork out billions more for the disaster caused a precipitous slide in the blue-chip's stock, hurting retirement savings for millions of Britons.