Abstract. National security becomes a strong determining factor while implementing trade policy measures, and this raises many legal and political questions. The article shows that, historically, the United States, as a Contracting Party to GATT 47, experienced serious domestic difficulties in developing rules regarding security exceptions. The confrontation between the U. S. Department of State and War Departments, who were charged with post-war U.S. military and defense planning, left its mark of ambiguity in the wording of some trade rules. In recent years, Washington has actively used trade restrictive measures, invoking articles on security exceptions in the World Trade Organization (WTO) rulebook. Panel report on the dispute “Russian Federation – measures in relation to transit of goods” contributed greatly to the interpretation of the relevant exceptions. At the same time, the definition of the “boundaries” of the use of such measures remains largely open. The urgency of the problem becomes even more evident when we note how the current discourse is shifting towards sources of national security problems other than military threats. In the long term, national security issues might be linked to food and energy security, and in the near future – to climate change. The deviation from the paradigm of multilateral liberalism towards economic nationalism requires rethinking of the approaches laid down in the foundation of the multilateral trading system. The author concludes that the United States is not interested in clarifying the WTO rules related to national security, while maintaining the status quo, which allows it to have wide policy space.