The global economic crisis places national economies under strain, and governments around the world may be tempted to support local producers and workers by putting in place protectionist policies. In spite of the formal G-20 promise to abstain from such steps, recent evidence shows that countries, including those from the G-20, have been introducing measures to the detriment of international trade and investment. Policies of this kind proved seriously harmful during the Great Depression of the 1930s. Today, the international legal landscape is markedly different but can it serve as an effective break on protectionism in crisis times? This article reviews relevant international disciplines in the areas of trade, investment and state aid and concludes that while the system will generally prevent protectionist policies, existing lacunae, ambiguous provisions and a lack of effective enforcement all indicate that it cannot be relied upon to provide a durable guarantee against economic nationalism, especially if the economic situation continues to deteriorate.