Enrichment under the NPT, JCPOA, and UNSR2231: A Legal and Political Reassessment in Light of Recent Developments
Sasan Karimi, PhD.
Deputy of International Horizons, PAIAB institute
International Politics Program Director, Nuclear Watch Network
Assistant Professor, University of Tehran
Introduction
The Treaty on the Non-Proliferation of Nuclear Weapons (NPT), established in 1968, continues to serve as the bedrock of international efforts to prevent the spread of nuclear weapons while promoting peaceful uses of nuclear energy. Central to ongoing debates is whether Article IV of the NPT confers any right to uranium enrichment—a process essential for producing nuclear fuel but also a potential pathway to weapons-grade material. In their August 15, 2025, article in the Bulletin of the Atomic Scientists, titled “Actually, the NPT Doesn’t Guarantee a Right to Make Nuclear Fuel,” Henry Sokolski and Sharon Squassoni contend that no such right exists, emphasizing historical opposition by nuclear-weapon states (NWS) and the proliferation risks inherent in fuel-cycle activities.
They argue that the NPT’s text lacks explicit endorsement of enrichment and that safeguards cannot reliably prevent diversions to military purposes. This perspective, however, overlooks the treaty’s foundational principles of sovereign equality and the absence of prohibitions on enrichment, interpreting political preferences as legal constraints. This essay critically evaluates Sokolski and Squassoni’s claims, drawing on the NPT’s legal text, historical context, and recent geopolitical events, including the June 2025 Israel-Iran conflict that involved strikes on Iranian nuclear facilities by Israel and the United States. These developments underscore the politicization of nuclear governance, where enforcement appears selective based on alliances rather than the impartial application of international law. By examining Iran’s nuclear program—uniquely recognized under the Joint Comprehensive Plan of Action (JCPOA) and UN Security Council Resolution 2231 (2015)—as a case study, the essay highlights how biases in nuclear discourse erode the NPT’s credibility and exacerbate global instability. Ultimately, it advocates for a recommitment to equitable norms to sustain the non-proliferation regime.
The Legal Framework of the NPT
Article IV, paragraph 1, of the NPT declares: “Nothing in this Treaty shall be interpreted as affecting the inalienable right of all the Parties to the Treaty to develop research, production and use of nuclear energy for peaceful purposes without discrimination and in conformity with Articles I and II of this Treaty.” This provision establishes a broad presumption of access to nuclear technologies for non-nuclear-weapon states (NNWS), contingent on non-proliferation safeguards administered by the International Atomic Energy Agency (IAEA). Critically, the treaty does not enumerate specific technologies like uranium enrichment or reprocessing, nor does it impose blanket restrictions on them. Under principles of international law, as articulated in the Vienna Convention on the Law of Treaties (1969), states retain sovereign rights unless explicitly limited by agreement. The absence of prohibitive language in the NPT thus implies that enrichment for peaceful purposes is permissible, provided it complies with IAEA verification. Sokolski and Squassoni counter that “nowhere in the treaty is any such ‘right’ mentioned” and that NPT negotiations lacked consensus on granting NNWS access to the full fuel cycle.
They cite historical documents, such as the 1946 Acheson-Lilienthal Report, which warned that enrichment and plutonium reprocessing are “too central to bomb-making” for safeguards to be effective, rendering inspections potentially misleading.
During NPT talks in the 1960s, proposals from countries like Great Britain and Sweden to prohibit fuel-making were debated but not adopted, and efforts to formalize a “right” to the entire fuel cycle failed.
However, this historical opposition reflects political concerns rather than legal consensus. The NPT’s drafters deliberately avoided prescriptive details on technologies to balance non-proliferation with development rights, particularly for the Global South. As legal scholar Daniel Joyner argues in Interpreting the Nuclear Non-Proliferation Treaty (2011), the treaty operates on a “permissive” model: prohibitions must be explicit, not inferred. Recent IAEA assessments reinforce this interpretation. In its May 2025 report, the IAEA noted Iran’s enrichment to 60% purity—beyond JCPOA limits but not prohibited under the NPT itself—while emphasizing that no diversion to military purposes had been detected prior to the June conflict.
The NPT’s safeguards system, while imperfect, provides a framework for verifying peaceful intent, countering claims that enrichment is inherently unverifiable.
The Political Dimension: Asymmetries and Double Standards in Nuclear Governance
The enrichment debate is inextricably linked to power imbalances in the global nuclear order. Sokolski and Squassoni’s analysis exemplifies a Western-centric narrative that presumes NNWS programs, especially in non-aligned states, are inherently suspect. They highlight Iran’s insistence on enrichment rights as a proliferation risk, noting U.S. historical vacillations—from near-granting reprocessing rights in the 1970s to opposition and eventual reluctant acceptance—while downplaying similar leniencies toward allies.
This selective scrutiny assumes, without any single evidence that programs like Iran’s are “military-oriented”, echoing a broader discourse that burdens NNWS with verification while NWS and non-NPT states evade comparable obligations. The June 2025 Israel-Iran conflict vividly illustrates these double standards. On June 13, Israel launched pre-emptive strikes against Iranian nuclear facilities, scientists, and Islamic Revolutionary Guard Corps military commanders, citing Iran’s alleged proximity to a nuclear weapon. The United States followed with aerial strikes on June 21–22 targeting Fordow, Natanz, and Esfahan, aiming to degrade Iran’s capabilities. Iran retaliated with missile strikes, but a ceasefire was announced on June 23. Israel, a non-NPT state with an estimated at least 90 nuclear warheads, faces no IAEA oversight, yet it initiated military action against an NPT signatory.
This disparity of tolerating Israel’s undeclared nuclear arsenal converts nuclear governance into a tool of geopolitics, prioritizing alliances over legal equity. Such actions perpetuate a system where NWS and their allies act as self-appointed “verifiers,” imposing costs on others for their own strategic anxieties. The Non-Aligned Movement has long criticized this as neo-colonial, arguing it undermines the NPT’s “grand bargain” of disarmament in exchange for technology access.
Iran’s Nuclear Program: Legitimacy Amid Escalation
Iran’s program exemplifies the tension between legal rights and political pressures. Under the JCPOA and UNSCR 2231, Iran’s enrichment activities were explicitly recognized, with defined limits on levels and stockpiles over a timeframe to ensure peaceful use. Prior to 2025, IAEA reports consistently found no evidence of diversion since 2003, per U.S. intelligence estimates.
The Israeli attacks of 2025, condemned by China and Russia and a large number of other states as violations of international law, highlight how military interventions bypass diplomatic frameworks, potentially driving proliferation rather than preventing it.
The Consequences of Inequitable Nuclear Norms
Selective enforcement erodes the NPT’s legitimacy, fostering instability. The 2025 conflict disrupted U.S.-Iran talks and escalated regional tensions, with risks of broader war.
By allowing non-NPT states like Israel to attack compliant programs, the international community signals that legal adherence offers no protection, incentivizing NNWS to reconsider NPT membership or pursue hedging strategies. This undermines global norms, as seen in stalled NPT Review Conferences and growing calls for reform from the Global South. Moreover, the strikes among others risk humanitarian and environmental catastrophes. In the long term, such actions destabilize the Middle East, where Israel’s arsenal—untouched by scrutiny—fuels an arms race.
Policy Recommendations
To mitigate these risks and restore equity:
- Hold Accountable Non-NPT Actors: The UN Security Council should investigate the 2025 strikes as violations of IAEA principles prohibiting attacks on nuclear facilities, imposing sanctions if warranted.
- Revive and Strengthen the JCPOA: Along with resuming U.S.-Iran talks with converting to P5+1 format, Iran and the E3 can come back to their obligations under the JCPOA.
- Promote Universal Disarmament: NWS must accelerate Article VI commitments, including arsenal reductions, to rebuild trust. Engage non-NPT states like Israel in confidence-building measures.
- Foster Multilateral Verification: Expand IAEA resources for impartial monitoring, reducing reliance on unilateral actions.
- Refrain from politicization of the IAEA and allow the Agency to be professional and impartial.
References
Joyner, D. H. (2011). Interpreting the Nuclear Non-Proliferation Treaty. Oxford University Press.
Sokolski, H., & Squassoni, S. (2025, August 15). Actually, the NPT doesn’t guarantee a right to make nuclear fuel. Bulletin of the Atomic Scientists. https://thebulletin.org/2025/08/actually-the-npt-doesnt-guarantee-a-right-to-make-nuclear-fuel/
Stockholm International Peace Research Institute. (2025). SIPRI Yearbook 2025: Armaments, disarmament and international security. Oxford University Press.
United Nations. (1968). Treaty on the Non-Proliferation of Nuclear Weapons. https://www.un.org/disarmament/wmd/nuclear/npt/text
United Nations Security Council. (2015). Resolution 2231 (2015) [On the Joint Comprehensive Plan of Action]. https://www.un.org/securitycouncil/content/resolutions-0
U.S. Intelligence Community. (2025). Annual threat assessment of the U.S. Intelligence Community. Office of the Director of National Intelligence. https://www.dni.gov/files/ODNI/documents/assessments/ATA-2025-Unclassified-Report.pdf
