As has been well documented, the International Atomic Energy Agency (IAEA) some time ago lost confidence that Iran's nuclear program is being carried out exclusively for peaceful purposes as required by the Nuclear Nonproliferation Treaty (NPT), to which Iran is a non-nuclear weapon state party. Iran became a party to the NPT in 1970, and concluded a safeguards agreement with the IAEA in 1974. Under the agreement, Iran accepted safeguards (IAEA inspections) for the purpose of verifying that nuclear material is not diverted to nuclear weapons or to other nuclear explosive devices.
In February of this year, the IAEA Board of Governors decided to submit a report to the U.N. Security Council on its difficulties with Iran. In its referral to the Security Council, the Board of Governors noted Iran's "many failures and breaches of its obligations to comply with its NPT Safeguards Agreement ...." The President of Iran, Mahmoud Ahmadinejad, has indicated that if the Security Council takes action against Iran, the NPT would become "invalid" vis-à-vis Iran.
Article X, paragraph 1 of the NPT provides:
Article 26 of the Iran-IAEA safeguards agreement provides, "This agreement shall remain in force as long as Iran is a party to the [NPT]." Consequently, if Iran lawfully withdraws from the NPT, the safeguards agreement would no longer be in force.
In January 2003, North Korea announced its withdrawal from the NPT because, it said, of the United States' hostile policy. Article 26 of the North Korea-IAEA safeguards agreement is the same, mutatis mutandis, as Article 26 of the Iran-IAEA agreement. The IAEA Board of Governors regards the North Korea-IAEA safeguards agreement as still being in force despite North Korea's stated withdrawal from the NPT, and so did the participants in the 2005 NPT Review Conference. The IAEA, though, has not been able to verify that North Korea is complying with its NPT obligations.
The legal issues raised by Iran's possible withdrawal are similar to the issues raised with regard to North Korea. The question regarding Iran's right to withdraw from the NPT under Article X, above, is not whether the NPT actually would become automatically "invalid" if the Security Council takes action against Iran (it wouldn't). Instead, Article X allows each party to make its own decision as to whether extraordinary events, related to the subject matter of the NPT, have jeopardized its supreme interests and, if so, whether it wants to withdraw from the treaty. Arguably, customary international law imposes a good faith requirement on the party deciding that extraordinary events have jeopardized its supreme interests. The Vienna Convention on the Law of Treaties says that "Every treaty in force is binding upon the parties to it and must be performed by them in good faith," a requirement that could be applied to a withdrawal provision in a treaty as well as to its more substantive provisions. The NPT does not establish any mechanism for making a determination as to whether a party has acted in good faith, but the IAEA Board of Governors and the 2005 NPT Review Conference implicitly made such a determination in the case of North Korea by treating the safeguards agreement as remaining in force.
If Iran withdraws from the NPT either lawfully or unlawfully, the Security Council could determine under Chapter VII of the U.N. Charter that there is a threat to the peace and could decide on measures to maintain or restore peace and security. The Security Council could then (for example) require Iran to cooperate with the IAEA under pain of sanctions if Iran fails to do so. The enforcement measures could include economic, diplomatic or even military sanctions. Any proposed resolution requiring Iran to cooperate or imposing sanctions against Iran, however, would be subject to a possible veto by any of the permanent Security Council members (China, France, Russia, the United Kingdom and the United States). So far, China and Russia have been unwilling to impose sanctions against Iran.
If and when the Security Council does act under Chapter VII, its decisions are binding on all U.N. members, including Iran.
Frederic L. Kirgis, an ASIL member, is Law School Association Alumni Professor Emeritus at the Washington and Lee University School of Law. He has written a book and several articles on United Nations law, and is an Honorary Editor of the American Journal of International Law.
 For a recap of Iran's relationship with the IAEA and its inspectors, see N.Y. Times, May 19, 2006, p. A1.
 The text of the safeguards agreement is in IAEA INFCIRC/214 (13 Dec. 1974).
 See IAEA Board of Governors Res. GOV/2006/14 (4 Feb. 2006).
 N.Y. Times, May 8, 2006, p. A8.
 See IAEA Report on the 2005 NPT Review Conference, Part 2, p. 4, and Part 5, p. 3, accessible at www.un.org/events/npt2005/presskit.pdf. The states participating in the 2005 NPT Review Conference said that the North Korea-IAEA safeguards agreement "remains binding and in force."
 Vienna Convention on the Law of Treaties Art. 26, 1155 U.N.T.S. 331. Iran is not a party to the Vienna Convention, but the performance-in-good-faith provision in it is regarded as a codification of custom.
 U.N. Charter Arts. 25 and 48. For more on Iran and the NPT, see two previous ASIL Insights: Iran, the IAEA and the UN (Nov. 2004); and Iran's Resumption of Its Nuclear Program (Aug. 22, 2005).