Non-discrimination is a fundamental principle of the World Trade Organization (WTO), which promotes global trade with the goal of eradicating hunger, reducing poverty, and ensuring global prosperity. According to the WTO rules, members are required to give other members most-favoured-nation and national treatment. Due to the military conflict between the Russian Federation and Ukraine, the United States, European Union, and several other member countries suspended most-favoured-nation treatment for Russian goods in mid-March 2022. This study examines the principle of non-discrimination under the WTO provisions, identifies relevant exceptions, analyses the Russia-Traffic in Transit case, and evaluates the appropriateness of the above actions by the US and others. Finally, this paper concludes that the US and its allies failed to present concrete evidence demonstrating a direct and causal relationship between the military situation in Ukraine and their own essential interests under Article XXI of GATT 1994.