The basic rules of international trade are simple. The United States and the European Union, the two major trading blocs, have each sought to curb serious health and environmental risks before they cause substantial harm. Both have promoted industrial policies to enhance the competitiveness of their industries and the global economy along with them. The institutional framework of the GATT and the WTO that evolved alongside the United Nations Charter has kept these competing aims in reasonable balance. It has also reflected the main global priorities of later eras: preserving peace and stability through international commerce and the rule of law.
Liberalizing international trade has thus remained one of the primary tenets of international relations. Trade restrictions have not generally been tolerated unless clearly legitimate objectives--such as human, animal and plant health, environmental protection, or national security--were seriously threatened and no alternative means of protecting them were available. Where countries have needed to enact apparently arbitrary regulations to preserve national interests--that is, in the absence of relevant international standards or substantially equivalent national standards--they have been required to justify their imposition: A legislating WTO party must prove through an empirical science-based risk assessment that the health or environmental hazard identified is "real" and poses significant harm to society.
