Iran, Nuclear Weapons, and International Law: What Might the Final Agreement Add?

Joseph Klingler
June 19, 2015


In early April, Iran, the European Union, and the so-called "P5 + 1" (China, France, Russia, the United Kingdom, and the United States, plus Germany) agreed on key parameters for resolving the longstanding conflict over Iran's nuclear program.  This framework agreement is not the end of the road; by its terms, "nothing is agreed until everything is agreed."[1]  Instead, the agreement merely sets the stage for details to be expressed in a final Joint Comprehensive Plan of Action (JCPOA) to be drafted by June 30, 2015.

The ongoing negotiations follow years of tension pitting Iran, which has long claimed sovereign rights to peaceful nuclear development, against a group of states expressing deep skepticism over Iran's true intentions.  Iran hopes to have sanctions lifted; its counterparts aim to prevent Iran from acquiring a nuclear weapon. 

This Insight explains why, under a number of heads of international law, it is already unlawful for Iran to acquire nuclear weapons.  In so doing, it addresses restrictions on Iran's freedom of action under: i) The Treaty on the Non-Proliferation of Nuclear Weapons; ii) Iran's unilateral acts; and iii) multiple United Nations Security Council Resolutions.  It then asks how, if Iran is already prohibited from acquiring nuclear weapons, the JCPOA is likely to further constrain any potential Iranian effort to acquire them. 

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT)

Iran ratified the NPT in 1970.[2]  Under Article II,

Each non-nuclear-weapon State Party to the Treaty undertakes not to receive the transfer from any transferor whatsoever of nuclear weapons or other nuclear explosive devices or of control over such weapons or explosive devices directly, or indirectly; not to manufacture or otherwise acquire nuclear weapons or other nuclear explosive devices; and not to seek or receive any assistance in the manufacture of nuclear weapons or other nuclear explosive devices.[3]

For verification purposes, Article II of the treaty also requires signatories to conclude safeguards agreements with the International Atomic Energy Agency (IAEA).[4]  Because such agreements are designed to verify only declared activity and materials, they may be supplemented by an Additional Protocol that can "provide assurances as to the absence of undeclared nuclear material and activities in a State."[5]  Although Iran's safeguards agreement is in force,[6] it has not yet ratified the Additional Protocol it signed in 2003.[7]

Article X of the NPT permits a state party "to withdraw from the Treaty if it decides that extraordinary events . . . have jeopardized the supreme interests of its country."[8]  Withdrawing states must "give notice of such withdrawal to all other Parties to the Treaty and to the United Nations Security Council three months in advance."[9]  Thus, while Iran is clearly currently forbidden from acquiring nuclear weapons under the NPT, it could (theoretically) choose to withdraw on three months' notice should it determine that its "supreme interests" have been jeopardized by "extraordinary events."[10]

Unilateral Acts

The NPT may not be the only mechanism through which Iran has voluntarily bound itself not to acquire nuclear weapons.  Indeed, Iran has at least arguably—and perhaps irrevocably—done so through the doctrine of so-called "unilateral acts."

The most famous discussion of the doctrine may be found in the Nuclear Tests case before the International Court of Justice, where the Court interpreted several French communications as creating a binding legal commitment on the part of France not to conduct further atmospheric nuclear tests.  According to the Court,

It is well recognized that declarations made by way of unilateral acts, concerning legal or factual situations, may have the effect of creating legal obligations . . . . When it is the intention of the State making the declaration that it should become bound according to its terms, that intention confers on the declaration the character of a legal undertaking . . . . An undertaking of this kind, if given publicly, and with an intent to be bound . . . is binding. In these circumstances, nothing in the nature of a quid pro quo, nor any subsequent acceptance of the declaration, nor even any reply or reaction from other States, is required for the declaration to take effect . . . .[11]

Iran has arguably made statements qualifying as binding unilateral acts.  On the basis of a fatwa banning nuclear weapons allegedly issued by Iranian Supreme Leader Ayatollah Khamenei more than eight years ago, Iran in January of 2013 sought to "spell out in its clearest terms yet that it is not seeking nuclear weapons."[12] According to an Iranian Foreign Ministry Spokesperson, "[w]hen the highest jurist and authority in the country's leadership issues a fatwa, this will be binding for all of us to follow."[13] Of course, the fact that a fatwa would be binding under Iranian domestic law does not mean that it would be binding under international law, and scholars have in any event noted that "a new fatwa [could] be issued that would basically nullify the previous one regarding the same issue."[14]  In any case, Iranian officials have clearly attempted to convince the world that Iran will never seek nuclear weapons.  Indeed, Iran's President has unequivocally stated that Iran is "not after weapons of mass destruction,"[15] and a spokesman has even gone so far as to offer to "register [Khamenei's] fatwa as an international document."[16]

Whether such statements are binding unilateral acts is open to debate.  But a plausible argument exists that, if the French statements were binding in the context of atmospheric nuclear testing, so must be Iran's statements regarding the acquisition of nuclear weapons.

Security Council Resolutions

Although Iran is clearly prohibited from acquiring nuclear weapons under the NPT, it could, as a theoretical matter, withdraw on three months' notice.  And although Iran has arguably created legal obligations through its unilateral commitments not to acquire nuclear weapons, such unilateral statements are a thin reed upon which to hang a legal case.  Thus, the strongest, most durable legal prohibition on Iran's freedom of action stems from resolutions issued by the Security Council under Chapter VII of the United Nations Charter. 

The first such prohibition was issued in 2006, after the IAEA referred Iran to the Security Council for alleged non-compliance with the NPT.[17] Resolution 1696, passed under Chapter VII and indisputably binding on Iran, "demand[ed]" that Iran "suspend all enrichment-related and reprocessing activities, including research and development, to be verified by the IAEA."[18]  It further "call[ed] upon Iran to act in accordance with the provisions of the Additional Protocol and to implement without delay all transparency measures the IAEA may request in support of its ongoing investigations,"[19] thereby significantly deepening the legal regime governing the country.  Over the next four years, five additional resolutions followed, incrementally expanding or reaffirming restrictions on Iran and Iranian officials.

The Joint Comprehensive Plan of Action

What, as a legal matter, is the final JCPOA likely to add?  According to the Obama administration earlier this year, the answer was "nothing."  In congressional testimony in March, Secretary of State John Kerry explicitly stated that the administration was "not negotiating a legally binding plan."[20]  When asked why the administration "would even bother . . . to negotiate something that neither it nor the Iranians nor any other member of the negotiating team is going to be bound to," the White House Spokesperson insisted that the "the success of this arrangement [will not] depend . . . on whether [the agreement is] legally binding or not."[21]

Yet the administration's view that the success of the agreement will not depend on whether it is legally binding is true, at best, only in form. In fact, the framework agreement itself explicitly states that that a Security Council resolution "will endorse the JCPOA and urge its full implementation."[22] The parties' use of the word "urge" leaves open whether the instrument will be legally binding.  But Iran, for its part, is clearly demanding an end to highly symbolic United Nations sanctions, and it is difficult to imagine how they could be lifted absent a Security Council resolution to that effect. 

A more difficult question may be whether the success of the final agreement depends on additional legal obligations for Iran. Although there have been calls for legal restrictions going beyond those that already exist,[23] many of Iran's core commitments under the framework agreement—such as those regulating its enrichment activities or requiring it to implement the Additional Protocol—do not actually impose anything new. Iran is already heavily restricted under international law—in some ways more so than it will be under the JCPOA.  Not only is it outright prohibited from acquiring nuclear weapons or engaging in enrichment-related activities, but it is also subject to extensive monitoring and reporting obligations under its NPT safeguards agreement and—albeit indirectly through Security Council resolutions—the Additional Protocol.   

If the Additional Protocol is, as the United States has described it, "the foremost international standard for safeguards that provides the IAEA with the authority to ensure that all nuclear material is used for peaceful purposes,"[24] one might question whether additional obligations are truly necessary.  On this view—which also happens to fit with the administration's position that the success of the agreement will not depend on whether it is legally binding and Iran's recent claim that Iran has "not accepted and will not accept any inspection system higher than [the] [A]dditional [P]rotocol"[25]—what is needed more than additional legal obligations is the political will to comply with those that already exist.  And while law can undoubtedly help create that will, for a proud country like Iran,[26] law freely agreed to may prove more effective than law imposed by the Security Council from above.


About the Author: Joseph Klingler is an associate in the international litigation and arbitration department of Foley Hoag LLP. He exclusively represents sovereign states before the world's principal dispute resolution bodies.

[1] Parameters for a Joint Comprehensive Plan of Action Regarding the Islamic Republic of Iran's Nuclear Program, U.S. Department of State (Apr. 2, 2015), [hereinafter Parameters for JCPOA].

[2] Esther Pan, IRAN: Curtailing the Nuclear Program, Council on Foreign Relations (May 13, 2004),

[3] Treaty on the Non-Proliferation of Nuclear Weapons, art. II, opened for signature July 1, 1968, 21 U.S.T. 483, 729 U.N.T.S. 161 (entered into force March 5, 1970), available at

[4] Id.

[5] IAEA Safeguards Overview, International Atomic Energy Agency (Oct. 14, 2014), (emphasis added).

[6] See generally Int'l Atomic Energy Agency [IAEA], The Text of the Agreement Between Iran and the Agency for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons, IAEA Doc. INFCIRC/214 (Dec. 13, 1974), available at

[7] See Conclusion of Additional Protocols: Status as of 14 May 2015, International Atomic Energy Agency, available at Although Iran has not yet ratified the Additional Protocol, it is nonetheless bound not to defeat its object and purpose under Article 18 of the Vienna Convention on the Law of Treaties.

[8] Treaty on the Non-Proliferation of Nuclear Weapons, supra note 3, art. X.

[9] Id.

[10] Such action is not unprecedented: North Korea controversially invoked Article X in withdrawing from the NPT in 2003.   See Frederic L. Kirgis, North Korea's Withdrawal From The Nuclear Nonproliferation Treaty, ASIL Insights (Jan. 24, 2003),

[11] Nuclear Tests Case (New Zeal. v. France), 1974 I.J.C. 457, 472 (Dec. 20).

[12] Iran: Religious DecreeAagainst NuclearWweapons is Binding, CBS News (Jan. 15, 2013, 10:15 PM),

[13] Id.

[14] Mike Shuster, Iran's Nuclear Fatwa: A Policy Or A Ploy?, NPR (June 14, 2012, 5:05 AM),

[15] Rouhani says Iran will not Acquire Nuclear Weapons 'on Principle', The Guardian (Mar. 1, 2014, 10:18 AM),

[16] Iran: Religious Decree Against Nuclear Weapons is Binding, supra note 12.

[17] Jason Starr, The U.N. Resolutions, United States Institute of Peace, (last visited June 18, 2015).

[18] See S.C. Res. 1696, ¶ 2, U.N. Doc. S/Res/1696 (July 31, 2006).

[19] Id. ¶ 6.

[20] Adam B. Lerner, State Department: Iran Deal 'Nonbinding', Politico (Mar. 11, 2015, 11:37 AM),

[21] Daily Press Briefing, Spokesperson Jen Psaki, U.S. Department of State (Mar. 12, 2015),   But see Adequate Verification Under a Comprehensive Iran Nuclear Deal: Testimony Before the House Subcommittee on the Middle East and North Africa, Committee on Foreign Affairs: "Iran's Noncompliance with its International Atomic Energy Agency Obligations," 115th Cong. 1 (2015) (statement of David Albright, President, Institute for Science and International Security).

[22] Parameters for JCPOA, supra note 1.

[23] See, e.g., Albright, supra note 21.

[24] Adam Scheinman, A Strong NPT Treaty: Our Best Hope for a World Without Nuclear Weapons, U.S. Department of State Official Blog (Apr. 7, 2015), (emphasis added).   See also IAEA, IAEA Safeguards Agreements and Additional Protocols: Verifying Compliance with Nuclear Non-Proliferation Undertakings (2001), available at

[25] Deputy FM: Iran not to Accept Beyond Additional Protocol, Islamic Republic News Agency (May 6, 2015),

[26] See Stephen Kinzer, Inside Iran's Fury, Smithsonian Mag., Oct. 2008 (referring to Iran as "one of the world's oldest and proudest nations"), available at