Abstract
Domestic support for a liberal commercial policy in the U.S. rests on a commonly accepted set of rules and norms. These rules and norms, best characterized as a defense of free and fair trade, arise from two different traditions. The first originated as a political reaction to high trade barriers preceding the Great Depression. Central decision makers took as a lesson from the depression period that short-term political forces should not determine the level of state intervention into the market. The second, to protect against unfair trade, emanates from a long history of state support for industries that claim foreign producers are pursuing unfair predatory practices. Established in statute before the Depression, these rules did not fundamentally change in the postwar period. Together, these decision rules are used to interpret American trade protectionism.