**Abstract**



The right of withdrawal from the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) is expressly recognized in Article X of the Treaty. Nevertheless, the recognition of such a right does not mean that its exercise is unrestricted or that a State may withdraw from the Treaty solely by making a unilateral declaration. Article X establishes substantive and procedural requirements for withdrawal, and the fulfillment of these requirements raises important questions concerning the legality and legitimacy of a State’s decision to terminate its participation in the NPT. In particular, the relationship between the exceptional circumstances invoked by a withdrawing State, the subject matter of the Treaty, the State’s supreme interests, and the procedural requirements of withdrawal requires a systematic legal assessment. Moreover, the exercise of the right of withdrawal must be considered in light of general principles of international law, including good faith and the prohibition of abuse of rights. Against this background, the central problem of this research is how the legitimacy of exercising the right of withdrawal from the NPT can be assessed through a coherent and criteria-based framework.



The main objective of this research is to propose an integrated model for assessing the legitimacy of the exercise of the right of withdrawal from the NPT by combining relevant criteria of international law with normative criteria derived from Imami Shi'a jurisprudence. The study does not consider Islamic jurisprudential rules to be substitutes for the rules of international law governing the NPT. Rather, Imami Shi'a jurisprudence is incorporated as a complementary normative framework, particularly for assessing the legitimacy of a State’s decision within the context of the legal order of the Islamic Republic of Iran. Accordingly, the research seeks to establish a structured relationship between the specific requirements of Article X of the NPT, the general principles governing the exercise of treaty rights under international law, and the relevant principles of Imami Shi'a jurisprudence.



The research employs a descriptive-analytical methodology and draws upon relevant sources of international law, treaty law, documents and materials concerning the NPT, as well as the principles and jurisprudential rules of Imami Shi'a jurisprudence. The analysis first examines the nature and scope of the right of withdrawal from international treaties and then focuses specifically on Article X of the NPT. The conditions contained in Article X are examined with particular attention to the occurrence of extraordinary events, the relationship between those events and the subject matter of the Treaty, the endangerment of a State’s supreme interests, and compliance with the procedural requirements for withdrawal. The study emphasizes that the existence of a recognized right of withdrawal should not be confused with the conclusion that every exercise of that right is necessarily legitimate. The manner in which the right is invoked and exercised must also be examined in light of the general legal framework applicable to treaty relations.



Within this framework, the principle of good faith and the prohibition of abuse of rights are considered as important criteria for assessing the conduct of a State exercising its right of withdrawal. The continued binding force of treaty obligations prior to a legally effective withdrawal is also taken into account. Accordingly, even where the conditions of Article X appear to be satisfied, the State’s conduct before and after the declaration of withdrawal may remain relevant to the legal assessment of its exercise of the right. The research therefore distinguishes between the existence of the right of withdrawal and the legitimacy of the particular manner in which that right is exercised.



The study further examines the potential role of necessity and proportionality as supplementary assessment tools. These concepts are not presented as independent and express conditions established by Article X of the NPT. Rather, they are used as complementary criteria for determining whether withdrawal was genuinely necessary in the circumstances invoked by the State, whether less burdensome alternatives were available, and whether the measure adopted bears a reasonable relationship to the circumstances and interests relied upon by the withdrawing State. This distinction is important because it prevents necessity and proportionality from being treated as additional textual requirements of Article X while allowing them to contribute to a broader assessment of the legitimacy of the State’s decision.



A further dimension of the research concerns the principles of Imami Shi'a jurisprudence. In this regard, the principles of fulfillment of obligations and the principle of binding force of contractual commitments are considered as the primary basis supporting the continuation of treaty obligations. At the same time, other jurisprudential principles, including the rule of nafy al-sabil (prohibition of domination), the rule of la darar (prohibition of harm), the rule of nafy al-haraj (removal of undue hardship), the principle of preservation of the system, and the principle of public interest, are examined according to their respective subject matter and conditions of application. These principles are not treated as automatic grounds for withdrawal. Rather, their relevance depends upon the existence and objective establishment of the circumstances necessary for their application. In particular, political disagreement, diplomatic pressure, or dissatisfaction with treaty obligations alone cannot, without further assessment, establish the exceptional circumstances required for reliance on such principles.



The findings demonstrate that the legitimacy of withdrawal from the NPT cannot be established solely through formal compliance with the procedural requirements of Article X. A comprehensive assessment must consider the substantive requirements of Article X, the general principles of international law governing the exercise of treaty rights, and the relevant normative criteria of Imami Shi'a jurisprudence. The research therefore proposes a three-level model for assessing the legitimacy of withdrawal. At the first level, the specific requirements of Article X are examined, including the occurrence of extraordinary events, their connection with the subject matter of the Treaty, the endangerment of the State’s supreme interests, and compliance with the required withdrawal procedures. At the second level, the exercise of the right is evaluated in light of general international law, particularly good faith, the continuing force of treaty obligations until their lawful termination, the prohibition of abuse of rights, and the legal consequences of withdrawal. At the third level, the State’s decision is subjected to a complementary normative assessment based on the relevant principles of Imami Shi'a jurisprudence.



The proposed model thus provides a structured framework for distinguishing between the mere existence of a right of withdrawal and the legitimacy of exercising that right in a particular case. The model also incorporates necessity and proportionality as supplementary assessment tools rather than as independent requirements of Article X. The central conclusion of the research is that a legitimate withdrawal from the NPT should not be understood merely as a unilateral political decision or as an act satisfying formal procedural requirements. Instead, its legitimacy should be assessed through the coordinated application of the specific conditions of Article X, the general principles of international law, the relevant principles of Imami Shi'a jurisprudence, and the supplementary assessment of necessity and proportionality. In this way, the proposed framework seeks to provide a more systematic and evaluable basis for determining the legitimacy of exercising the right of withdrawal from the NPT.