Iran's Nuclear Program: Tehran's Compliance with International Obligations

Key Chapter Title List

1. Introduction and Background
2. Implementation and Evolution of the Joint Comprehensive Plan of Action (JCPOA)
3. Potential Non-Compliance Post-JCPOA: Design Information Provision
4. Potential Non-Compliance Post-JCPOA: Undeclared Nuclear Material
5. Iran and the United Nations Security Council
6. Legal Basis for IAEA and UN Security Council Actions
7. Has Iran Violated the Treaty on the Non-Proliferation of Nuclear Weapons (NPT)?
8. Appendix A: Iran's Compliance with JCPOA Nuclear Program Restrictions
9. Appendix B: IAEA Special Inspections
10. Appendix C: Iran's Violations of its IAEA Safeguards Agreement
11. Appendix D: List of Cited IAEA Reports
12. Appendix E: William Foster's Extended Commentary on Possible Article II NPT Violations

Document Introduction

This report, prepared and updated on January 16, 2025, by the Congressional Research Service (CRS) of the United States, aims to provide a comprehensive and objective legal and policy analysis of the compliance status of the Islamic Republic of Iran's nuclear program. The report's core focus is on Tehran's fulfillment of its international obligations, which primarily stem from its Comprehensive Safeguards Agreement as a state party to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), relevant United Nations Security Council resolutions, and the Joint Comprehensive Plan of Action (JCPOA) reached in 2015. The report serves legislative debate, offering policymakers, researchers, and security analysts an in-depth assessment based on publicly available international verification reports and legal texts.

The report first reviews the origins of international concern regarding Iran's nuclear program, focusing on proliferation worries triggered by its uranium enrichment activities and heavy water reactor construction. Since the exposure of its clandestine nuclear activities in 2002, investigations by the International Atomic Energy Agency (IAEA) have revealed multiple instances of Iran violating its safeguards agreement, leading the IAEA Board of Governors to refer the matter to the UN Security Council in 2006. The Security Council subsequently adopted several legally binding resolutions requiring Iran to take measures to address international concerns. The report details the series of negotiations and cooperation between Iran and the IAEA, as well as the P5+1 (the five permanent UN Security Council members plus Germany), from 2003 to 2015, aimed at clarifying historical issues and suspending related activities, which ultimately led to the conclusion of the JCPOA.

The core section of the report provides an in-depth analysis of the implementation, evolution, and current predicament of the JCPOA. The JCPOA imposed strict limitations on Iran's nuclear activities, including enrichment levels, stockpiles, the number and types of centrifuges, heavy water stockpiles, and the modification of the Arak heavy water reactor. The IAEA was tasked with verifying and monitoring these limitations. The report notes that from 2016 to mid-2019, parties confirmed that Iran was largely fulfilling its JCPOA obligations. However, starting in July 2019, Iran began to gradually and selectively cease performing multiple JCPOA commitments, including exceeding enrichment stockpile and level limits, installing and operating more advanced centrifuges, ceasing implementation of the Additional Protocol and the modified Code 3.1 of the Subsidiary Arrangements to its Safeguards Agreement. Citing IAEA Director General quarterly reports, the report meticulously documents these specific activities "beyond JCPOA limits," and analyzes Iran's legal rationale for invoking JCPOA Articles 26 and 36 to justify its actions, as well as the response of the E3 (France, Germany, the UK) in triggering the Dispute Resolution Mechanism (DRM).

Furthermore, the report specifically assesses other potential non-compliance by Iran outside the JCPOA framework. This includes its unilateral suspension of the modified Code 3.1 (concerning the timely provision of design information for new nuclear facilities), and the issue of "undeclared nuclear material and activities" arising from the IAEA's discovery of anthropogenic uranium particles at three undeclared locations. The report points out that although Iran has provided some cooperation and information, the IAEA Board of Governors, in multiple resolutions, has considered the relevant issues not fully resolved and has continuously urged Iran to provide full cooperation. The November 2024 IAEA Board resolution further requested the Director General to submit a comprehensive assessment report in the spring of 2025 regarding possible undeclared nuclear material in Iran.

On the legal front, the report systematically outlines the procedures for the IAEA Board of Governors to determine non-compliance and report to the Security Council according to its Statute, as well as the legal basis for the UN Security Council to impose sanctions on Iran and demand action under Chapter VII of the UN Charter (particularly Article 41). The report also explores the complex question of whether Iran has violated the NPT itself. The analysis references past U.S. government assessments based on "activity intent" and notes the current judgment of the U.S. intelligence community that Iran has not decided to manufacture a nuclear weapon, while emphasizing that the NPT itself lacks a formal mechanism for determining violations, and the Security Council has never formally declared Iran in violation of the NPT.

This report is based on extensive primary source documents, including successive IAEA Director General reports to the Board (GOV series), UN Security Council resolution texts, JCPOA agreement provisions, correspondence and joint statements between Iran and the IAEA, among others. The appendices provide detailed data support, such as specific indicators of Iran's violations of JCPOA limits, procedures for IAEA special inspections, details of historical safeguards violations, and lists of relevant reports. Overall, this report presents a dynamic and complex picture: the legal and verification framework for Iran's nuclear program has shifted from being centered on Security Council sanction resolutions to being centered on the JCPOA and Security Council Resolution 2231. However, this framework is now facing severe challenges due to Iran's gradual withdrawal and a series of unresolved safeguards issues, significantly hindering international efforts to restore confidence in the exclusively peaceful nature of its nuclear program.