Chickens slaughtered in the United States, claim officials in Brussels, are not fit to grace European tables. No, say the American: our fowl are fine, we simply clean them in a different way. These days, it is differences in national regulations, far more than tariffs, that put sand in the wheels of trade between rich countries. It is not just farmers who are grumbling about the unfairness they see in the global economy. An electric razor that meets the European Union's safety standards must be approved by American testers before it can be sold in the United States.