CoRPORATE America’s profit engine has been remarkably robust over the past few years, even amid stubborn inflation and elevated interest rates. Faced with Donald Trump’s assault on global trade, however, it is starting to sputter. Companies from General Motors, a carmaker, to Nike, a sportswear brand, have seen their profits plummet owing to Mr Trump’s levies on imports. Goldman Sachs, a bank, reckons that American businesses are absorbing around three-fifths of the cost of the duties.