One of the most controversial aspects of the negotiations at the World Summit on Sustainable Development in 2002 was an attempt by some delegations to require that multilateral environmental agreements be made fully compatible with trade rules before they could be ratified. Four years on, the environmental community remains fearful that trade will destroy years of environmental achievement, and the trade community that green measures will restore the obstacles to trade is has tried to remove through negotiations. While the Doha round of negotiations under the World Trade Organisation has done little to break this impasse, it has contributed to a growing awareness that trade regulations have to be harmonised with other public policy obligations, including environmental ones.