In the late 1990s the European agri-food system was thrown into disarray by widespread public protests against genetically modified (GM) crops and foods. These protests led large food retailers to remove GM ingredients from their own-brand products. In 1999, in an effort to regain control, EU politicians imposed an unofficial de facto moratorium on the approval of new biotechnology products. They made it clear that this moratorium would remain in place until new and revised legislation restored public confidence. In the months and years that followed, however, the US continued to approve and commercialise new GM crops and foods and a regulatory gap opened up; products that were approved in the US could not be sold in the EU. Transatlantic trade was soon disrupted and in 2003 the US finally took a case to the World Trade Organization. This gave the WTO one of its most high-profile and politically difficult disputes.