This paper develops a simple model to investigate linkages between trade and environmental policy. In the case of purely local pollution, trade liberalization without constraints on environmental policy induces a non-cooperative game between countries in pollution policy. Without any agreement on environmental policy, trade negotiations are unlikely to lead to a point on the Pareto frontier. When pollution is global, countries may be expected to disagree on linkages between trade agreements and environmental agreements. Countries importing pollution-intensive goods have an incentive to try to link trade agreements with environmental agreements, while countries exporting pollution-intensive goods have an incentive to try to obtain a binding commitment to free trade prior to negotiations over global pollution.