The European Union seems an unorthodox champion of free trade. Beyond a few purveyors of handbags and slimming drugs, few of its big companies compete successfully with rivals from America and China, the world’s two biggest economies. Negotiating a trade agreement with the EU means that countries halfway across the world have to sulkily accept that champagne can come only from the northern region of France or feta cheese from Greece. Back in Europe, the merest hint of a free-trade deal causes farmers from across the continent to descend on Brussels and pummel Eurocrats with eggs and manure.