GaTT had originally negotiated tariff concessions between members and the definition of a code of conduct and procedures for resolving trade disputes through negotiations. The central assumption underlying U.S. participation in these efforts to promote multilateral trade agreements was that international trade and investment cooperation has created harmonious political relations and eased tensions between nations. The GATT was based on the principles of non-discrimination and multilateralism in international trade. Non-discrimination was expressed by the unconditional status of the most favoured nation for all contracting parties. This agreement must reduce tariffs on imports from one country and reduce the tariff on all imports of the same products from other GATT countries. The most favoured contracts had been the preferred instrument for the United States in its relations with China in the 19th century, when the United States entered the Chinese market on the back of British imperialism. Indeed, most contracts with most recipient countries have been favoured throughout the history of the United States, and GATT has been only the recent embodiment of this mechanism for expanding trade opportunities. Multilateralism in the 1950s and 1960s encouraged the expansion of American groups around the world, but in the 1970s and 1980s, free trade meant that the United States was subject to stiff competition from the revamped economies of Western Europe and Japan.
First, Washington has tried to preserve its advantage by encouraging the extension of GATT rules to non-traditional areas. GATT has encouraged a series of multinational trade negotiations („cycles“) aimed at phasing out tariffs and eliminating unfair trade practices. During the Uruguay Round (1986-1994), which brought together 117 countries, the GATT agreement was extended to areas such as services, patents, trademarks, copyright and, above all, agriculture. At its last session (held on 7 April 1994 in Marrakech, Morocco), the Uruguay Round also created the World Trade Organization, which was to assume the management functions of the GATT from 1 January 1995. On December 7, 1994, Congress passed the implementation of the agreement. Confidence helped avoid victoryless trade wars in the 1930s. If governments believe that others will keep their trade barriers within agreed limits, they will do the same. They will be in a much better setting to work together. The GTT pillar, in article I, is the Most Favoured Nation (MFN) which requires all signatories to give all members the same commercial treatment as each member. For the original architects of the GATT post-war system, bilateral agreements were an abomination. They believed that the network of special agreements concluded by Germany, Britain and Japan after the First World War had contributed to the political tensions that fuelled the Second World War.
In addition, they found that bilateral or regional agreements generally do not cause more harm to members than they do.