Chinese enterprises, such as Huawei, have been severely affected by sanctions. In 2019, Huawei’s inclusion on the Entity List prohibited any foreign company using US technology from supplying it without approval, severely disrupting its global supply chain. This article interprets the national security exceptions (GATT Article XXI) in the USChina trade conflict. Through a doctrinal analysis of key rulings (e.g., Russia – Traffic in Transit), it constructs a three-factor review framework based on essential security interests, necessity, and emergencies in international relations. This framework is then applied to a comparative case study of US and Chinese sanctions practices. The analysis finds that while US extraterritorial sanctions frequently fail the necessity test, China’s counter-sanctions align more closely with the exception’s traditional scope. The article argues that the proportionality principle is vital to prevent abuse. By applying nascent DSB jurisprudence to a major contemporary dispute, this study provides a balanced framework for assessing the WTO-consistency of sanctions and suggests reinforcing the MPIA to reconcile sovereignty with multilateralism.

I. Introduction
II. Impact of Unilateral Trade Sanctions on the WTO
    A. The Challenge of the National Security Exception under theWTO System: Russia-Traffic in Transit
    B. Unilateral Sanctions as Compound Trade Barriers
    C. The Crisis of Generalization of the WTO Security ExceptionClause
III. Judicial Review of the WTO National SecurityException Clause
    A. The Starting Point for Judicial Review of the NationalSecurity Exception Clause
    B. Principles of Judicial Review of National Security Exceptions
    C. A Dual Review Method: Integrating Substantive andProcedural Scrutiny
    D. The Complementary Role of the Multi-Party InterimAppeal Arrangement
IV. Applying the Framework: A Legal ComplianceReview of the US and Chinese Practices
    A. The US’s Unilateral Sanctions under the TripartiteFramework Scrutiny
    B. China’s Responsive Counter-Sanctions under theTripartite Framework Scrutiny
V. Summary and Conclusion

• Youyou Jiang(Lecturer at School of Law and Politics of Nanjing Tech University)