1. Shared Interests and Disagreements During the Cold War
In the 1960s, the risk of nuclear war and the prospect of more nuclear-armed states made non-proliferation a major subject of international negotiation. The Eighteen-Nation Committee on Disarmament in Geneva was the principal negotiating forum. The United States and Soviet Union played key roles, but non-nuclear-weapon states also demanded that the framework include their interests.
On November 19, 1965, the United Nations General Assembly adopted Resolution 2028 (XX), stating that a treaty should avoid loopholes permitting proliferation, establish an acceptable balance of responsibilities between nuclear and non-nuclear states, and be a step toward nuclear disarmament. From the outset, negotiations thus concerned not only non-nuclear states renouncing weapons but also the obligations of existing nuclear powers.
2. Verification Provisions Were More Than a Technical Annex
Disputes centered on the scope of prohibited transfers, development of peaceful nuclear energy and who would inspect relevant activities. The European Atomic Energy Community already had regional safeguards, and its members worried about how the International Atomic Energy Agency's authority might affect their industries and existing arrangements. Agreement in principle between Washington and Moscow could not substitute for consultation with other states.
On November 2, 1967, U.S. Arms Control and Disarmament Agency director William Foster met Soviet ambassador Anatoly Dobrynin in Washington. Foster explained that the United States first had to coordinate Article III with European allies, while the Soviet side wanted explicit provision for IAEA safeguards. The treaty's duration and amendment procedure also drew questions. The record depicts a text still under negotiation, not a settled agreement already accepted by all.
References: [2]
3. Approval, Signature and Entry into Force Were Three Stages
On June 12, 1968, the General Assembly endorsed the treaty text through Resolution 2373 (XXII). On July 1, it opened for signature in London, Moscow and Washington. The United Kingdom, Soviet Union and United States became depositaries responsible for receiving and notifying instruments of ratification, accession and related documents. The assembly's political support and a state's consent to be bound were not the same legal act.
Article IX required signatories to ratify and deposit their instruments; initial entry into force required the three depositaries and forty additional signatories to complete the prescribed procedures. Once those conditions were met, the treaty entered into force on March 5, 1970. The United Kingdom had deposited its ratification in 1968, while the United States and Soviet Union did so on the entry-into-force date. For states joining later, binding effect followed their respective deposit dates.
4. Asymmetric Obligations and Shared Commitments
Articles I and II respectively prohibited nuclear-weapon states parties from transferring nuclear weapons or control over them, or helping non-nuclear states manufacture or acquire them, and committed non-nuclear-weapon states parties not to receive, manufacture or otherwise acquire such weapons. Article IX defined a nuclear-weapon state for treaty purposes as one that had manufactured and exploded a nuclear weapon or other nuclear explosive device before January 1, 1967.
At the same time, Article IV recognized the right to peaceful nuclear research, production and use subject to relevant treaty obligations, and called for exchange and cooperation. Article VI required parties to negotiate in good faith on effective measures concerning an end to the nuclear arms race, nuclear disarmament and related objectives. The treaty thus linked non-proliferation, peaceful use and disarmament, but did not prescribe a timetable for immediately destroying all nuclear weapons.
References: [4]
5. Turning Article III into an Operating System
Article III required non-nuclear-weapon states parties to conclude safeguards agreements with the IAEA for verification of relevant nuclear material in their peaceful activities. After the treaty established the obligation, reporting, nuclear-material accountancy, inspection and confidentiality arrangements still had to be negotiated. In 1970–1971, the agency's Safeguards Committee developed guidelines for the structure and content of these agreements, producing the framework later published as INFCIRC/153.
In a 1971 article, participating diplomat Werner Ungerer noted that states debated not only effective inspection but also costs and industrial secrets. Finland's relevant safeguards agreement with the agency was signed on June 11, 1971 and entered into force on February 9, 1972, an early example of moving from treaty commitment to specific arrangements. The agency acquiring responsibilities, states concluding agreements and actual verification beginning must be examined separately.
6. Compliance Required Continuing Review
Drawing on agency archives, historian Elisabeth Roehrlich argued that the negotiations of 1970–1971 involved more than technical implementation: they also redrew boundaries between international verification and national sovereignty. Safeguards could check declarations, identify problems and provide reports, but were not an automatically enforcing world police system. Nor did treaty membership alone establish that every obligation had been fulfilled.
The treaty established review procedures and required a decision on extension twenty-five years after entry into force. On May 11, 1995, parties in New York decided to extend it indefinitely, while adopting related arrangements including stronger review. Long-term continuation did not remove its original tensions: limiting additional nuclear weapons, protecting peaceful nuclear cooperation and advancing nuclear disarmament required continuing examination through different procedures.