Negative Security Assurances (NSAs)
Proposed Internationally Legally-Binding Negative Security Assurances (NSAs)
NSAs are the promise of nuclear weapon States (NWS) not to use or threaten to use nuclear weapons against non-nuclear-weapon States (NNWS)
Negative Security Assurances (NSAs) are part of the permanent agenda of the Conference on Disarmament (CD), and the possibility of recommending an internationally legally binding instrument has been included in proposals for a program of work in the CD. A number of States would prefer that negotiations take place in the context of the Nuclear Nonproliferation Treaty (NPT).
NSAs are the promise of nuclear-weapon States (NWS) not to use or threaten to use nuclear weapons against non-nuclear-weapon States (NNWS). In contrast, a positive security assurance is a pledge by NWS to provide immediate assistance, in accordance with the UN Charter, to a NNWS that is the victim of an act or threat of aggression in which nuclear weapons are used.
Although the five NPT NWS have made various pledges regarding NSAs, each has been either non-binding, limited in scope, or qualified in some way. The NPT NNWS have consistently pushed for NSAs in the form of a free-standing treaty or a protocol to the NPT. The demand for such a commitment has increased in recent years, particularly from the Non-Aligned Movement. These States seek assurances that are legally binding, unconditional, and apply to all NPT NNWS. The hesitation from the NWS stems from their concern that a binding, universal NSA treaty would constrain their military options for dealing with unforeseen events and weaken the security umbrellas they provide around the world.
The non-aligned States first sought NSAs during the NPT negotiations. UN General Assembly Resolution 21/53A called upon the Eighteen-Nation Committee on Disarmament “to consider urgently the proposal that nuclear weapons powers should give an assurance that they will not use, or threaten to use, nuclear weapons against non-nuclear weapons states without nuclear weapons on their territories.” The United States rejected this proposal, fearing it would allow the Soviet Union to threaten West Germany unless the United States withdrew its nuclear weapons from German bases.
The first legally binding NSAs were provided in Additional Protocol II of the Treaty of Tlatelolco (1967), which established the nuclear-weapon-free zone (NWFZ) in Latin America and the Caribbean. Though the assurances were not universal, this set an important precedent that NSA protocols constitute a key element of NWFZ treaties. A 1999 UN Disarmament Commission report on establishing NWFZs noted that nuclear-weapon States should “…through the signing of relevant protocols, enter into binding legal commitments not to use or threaten to use nuclear weapons against the States that belong to the nuclear-weapon-free zone.” Although NWFZs now cover more than half of the world’s land mass and 116 countries, most of the NSA protocols have not been ratified by the all the NWS. The United States has not ratified the NSA protocol to any NWFZ treaty except Tlatelolco, and Russia has only ratified the NSA protocols to the treaties of Tlatelolco and Rarotonga.
In 1978 the General Assembly’s First Special Session on Disarmament adopted a final document which noted that “effective arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons could strengthen the security of those States and international peace and security.” Each NWS then issued unilateral, non-binding assurances, which in some cases were qualified.
The Conference on Disarmament (CD) began addressing the issue of NSAs in 1980. From 1983 to 1994, the CD established an ad hoc committee to discuss NSAs. After a hiatus of four years, the CD reconvened the committee in 1998, but made no progress regarding negotiations towards a legally binding instrument. Since 1999, no ad hoc committee has been convened in the CD to work on the issue of NSAs, despite calls for it from numerous CD members and no objection in principle from any delegation. The program of work adopted in 2009 after years of consultations established a working group to discuss NSAs “with a view to elaborating recommendations dealing with all aspects of this agenda item, not excluding those related to an internationally legally binding instrument.”
The issue of negative security assurances also continues to be raised in the NPT context. In the run-up to the 1995 Review and Extension Conference, the NWS issued harmonized non-use declarations to the NNWS through unilateral statements which were subsequently noted in UN Security Council Resolution 984 (1995). However, with the exception of China, these assurances were conditional. For example, the United States declared that if a NNWS attacks the United States and is allied or associated with a NWS then nuclear weapons could be used against the NNWS. In 2003, the New Agenda Coalition tabled draft text as a possible basis for negotiating a legally binding instrument on NSAs. The working paper noted that while all NPT NNWS should be beneficiaries of a binding instrument, the assurances would “in certain circumstances be qualified.”
Every year since 1990, Pakistan has introduced a resolution on NSAs in the UN General Assembly.
Under an international legally binding instrument of negative security assurances, the five nuclear weapon states (China, France, Russia, United Kingdom, and United States) would pursue efforts to conclude appropriate, effective arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons. Presumably, these assurances would be reflected in domestic policy and military doctrine.
In January 2022, the CD adopted its agenda for 2022 which included NSAs. Like in previous years, the agenda item stated: “Effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.”
In August 2022, three of the NWS—France, the United Kingdom, and the United States—issued a joint statement on security assurances, in which they reaffirmed their “existing national security assurances regarding the use or threat of use of nuclear weapons against NNWS Parties to the NPT.” They also confirmed that by ratifying relevant protocols to the treaties establishing nuclear-weapon-free zones, they “have undertaken legally binding obligations to respect the status of such zones and not to use or threaten to use nuclear weapons against States Parties to such treaties.”
The NPT Review Conference in August 2022 highlighted the ongoing disagreements by states regarding the negotiation of legally-binding NSAs. In contrast to other NWS, at the conference, China called for states to “support the Conference on Disarmament in negotiating a legally binding international instrument on negative security assurances”.
In October 2022, in its updated Nuclear Posture Review, the United States reaffirmed that it “will not use or threaten to use nuclear weapons against non-nuclear weapon states that are party to the NPT and in compliance with their nuclear non-proliferation obligations.”
The 2021 agenda for the Conference on Disarmament was released on 19 January, which included NSAs.
On 27 January, the 2020 agenda for the Conference on Disarmament was released and included NSAs.
The Pakistani delegation resubmitted a draft resolution entitled “Conclusion of effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons” to the First Committee on 7 October. Originally submitted in 2015, the draft resolution underlines the need to conclude an effective international agreement on NSAs at an early date.
On 23 January, the 2019 agenda for the Conference on Disarmament was released and reaffirmed the discussion of NSAs.
During the 2019 NPT PrepCom, held 29 April to 10 May 2019 at United Nations Headquarters in New York, members of the Group of Non-Aligned States parties to the NPT submitted a working paper(NPT/CONF.2020/PC.III/WP.15) regarding negative security assurances. The delegations of Iran and China submitted separate working papers on the issue, NPT/CONF.2020/PC.III/WP.8 and NPT/CONF.2020/PC.III/WP.36 respectively.
On 19 June, Iraq delivered a statement to the Conference on Disarmament on behalf of the Group of 21 underlining, inter alia, the Group’s commitments to the conclusion of an instrument on NSAs. On 3 September, the Group of 21 submitted a statement to the conference on the matter stressing that a universal and legally binding instrument on NSAs “should be vigorously pursued.”
On 21 October, Pakistan resubmitted a draft resolution on NSAs to the First Committee.
On 23 January, the 2018 agenda for the Conference on Disarmament was released and reaffirmed the discussion of NSAs.
On 2 February, the U.S. released the 2018 Nuclear Posture Review. The Review reiterated past negative security assurances, stating that the U.S. “will not use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the NPT and in compliance with their nuclear non-proliferation obligations.”
On 21 February, Sri Lanka re-submitted a working paper on NSAs to the Conference on Disarmament originally submitted on 21 February 2017.
On 3 August, Vietnam submitted a working paper to the Conference on Disarmament on behalf of the G-21.
On 24 January, the agenda for the Conference on Disarmament reaffirmed the discussion of NSAs.
On 21 February, Sri Lanka submitted a working paper on NSAs to the Conference on Disarmament.
On 26 January, the agenda for the Conference on Disarmament reaffirmed the discussion of NSAs.
On 3 August, Mongolia submit a working paper on behalf of Member States of G-21 to the Conference on Disarmament.
On 20 January, the Agenda for the 2015 Session for the Conference on Disarmament reconfirms discussion of NSAs.
On 10 March, the Conference on Disarmament discussed NSAs. Participating states expressed their national positions on NSAs. The Women’s International League for Peace and Freedom (WILPF) announced that, due to the Conference’s inability to facilitate anything substantial, WILPF would cease engagement with the Conference.
On 19 March, Informal Civil Society Forum on the Conference on Disarmament included an interactive panel discussion on NSAs. The Chairman delivered a summary, addressing alternative approaches in the absence of legally-binding NSAs.
During the 2015 NPT Review Conference (27 April–22 May 2015), NSA issue was discussed. The Draft document of Subsidiary Body 1 addresses negative security assurances in the context of encouraging State Parties to ratify NWFZ treaties and withdraw any reservations by the 2020 Review Conference.
On 20 October the Pakistani delegation gave a statement to the First Committee in which it stated that they believed progress in the field of NSAs would help to ease the current strain on the topic of disarmament. Pakistan presented a draft resolution, which was co-sponsored by a number of other states, titled “Conclusion of effective international arrangements to assure non-nuclear-weapons States against the use or threat of use of nuclear weapons” which reaffirms the urgent need for NSAs.
On 21 January, at the Conference on Disarmament (CD), the United States made reference to the possibility of discussing the agenda item of NSAs, but made no direct mention.
On 18 June, Ambassador and Permanent Representative to the CD Henk-Cor van der Kwast made a statement concerning the role of NSAs and their relation to the Non-Proliferation Treaty.
During the first session of the Conference on Disarmament (CD) from 21 January–29 March, statements regarding NSAs were delivered by the delegations of the European Union, Iran, Japan, United States, Myanmar on behalf of ASEAN, Kazakhstan, Algeria, China, India, Syria, Turkey, Democratic Republic of Korea (DPRK), Pakistan, Russian Federation, Chile, and the Republic of Korea. Delegations expressed a wide acceptance that NSAs would be a good contribution to nuclear disarmament, as well as stability and confidence. United States noted that it has provided such assurances to states that have renounced nuclear weapons and that are in full compliance with their nuclear non-proliferation obligations. Russia also observed that it is prepared to engage in efforts to develop NSAs with the NPT members. Again NNWS reiterated that despite NSAs, they do not protect their security more than a world free of nuclear weapons. Many NNWS again called for a legally-binding treaty that would guarantee that nuclear weapons wouldn’t be used on NNWS.
On 11 February, a proposal for a program of work for the 2013 session was submitted by the president of the CD. A portion of the program sought the creation of a working group on “Effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.”
During the 2013 NPT PrepCom held 22 April–3 May 2013 in Geneva, Switzerland, members of the Non-Proliferation and Disarmament Initiative submitted a working paper regarding NWFZs and negative security assurances (NPT/CONF.2015/PC.II/WP.24). NAM and the Islamic Republic of Iran also submitted separate working papers on security assurances against the use or threat of use of nuclear weapons, NPT/CONF.2015/PC.II/WP.15 and NPT/CONF.2015/PC.II/WP.38 respectively.
The second session of the CD took place from 13 May until June 28. The body was unable to agree upon a program of work, resulting in minimal discussion of NSAs. Several states, including Iran, Cuba, Pakistan, Ecuador, Zimbabwe, and Kazakhstan, addressed NSAs in their statements at plenary meetings.
On 27 May, the delegation from Iran formally assumed the presidency of the CD. In his opening remarks on 28 May, Mr. Mohsen Naziri Asl acknowledged the importance of NSA discussions under the previous Indonesian CD presidency.
On 18 June, the CD was addressed by Ranjan Mathai, Foreign Secretary of India, and Kassym-Jomart Tokayev, Secretary-General of the CD. Both speakers noted that the inability of the CD to adopt a program of work hindered the ability of States to make progress on crucial disarmament issues including NSAs.
On 21 June, a program of work was submitted to the CD. The document proposed the creation of a working group called “Effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.” However, this program of work failed to be adopted by consensus.
On 25 June, Hoshyar Zebari, Foreign Minister of Iraq, addressed the CD. He noted that NSAs should not be considered as an alternate to nuclear disarmament and urged the CD to adopt a legally-binding NSA framework as soon as possible.
On 30 July, the third session of the CD took place under the presidency of Ambassador Mohammad Sabir Ismail of Iraq. .
On 20 August, the representative of Pakistan gave a statement to the Conference on Disarmament clearly expressing that it was ready to go outside the Conference on Disarmament but only on issues of interest to Pakistan regarding negative security assurances.
The 2014 session of the Conference on Disarmament will take place in January.
During the first session of the CD in 2012, discussion of NSAs was limited as the body was unable to reach agreement on a program of work. However, the official statements of several countries called for substantive discussions on NSAs, including Mongolia, Ukraine, Bangladesh, the Russian Federation, and New Zealand.
During the May 2012 NPT Review Conference, significant debate was focused on NSAs, often in the context of conversations centered around nuclear-weapon-free zones.
On 12 June, the CD held a thematic discussion on NSAs. Despite the CD’s deadlock on a program of work, no state actively opposed the establishment of a working group on NSAs. While several states noted the inclusion of legally-binding NSAs in the protocols to NWFZs as a significant measure, others cautioned that neither NWFZs nor unilateral statements by NWS could substitute for a universally binding agreement. Algeria also noted that unilateral statements could be withdrawn at any point.
The thematic discussion was continued on 7 August in which delegations reaffirmed their respective positions which are recorded in the plenary session records (CD/PV.1261 and CD/PV.1266).
On 30 August 2012, the Syrian Arab Republic on behalf of the member States of G-21 submitted a working paper (CD/1940) on negative security assurance.
On 3 December, the U.N. General Assembly adopted A/RES/67/29 on Conclusion of effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.
The CD addressed NSAs in a thematic discussion on 10 February. Delegates expressed an overwhelming support for legally binding NSAs, but disagreement emerged over the context in which NSAs should be pursued. The United States in particular encouraged the use of legally binding NSAs within the protocols to the nuclear-weapon-free zone treaties, while other states argued for the creation of a special treaty on negative security assurances. There was also significant debate on the appropriate venue for such negotiations and if it should remain within the CD or be added to the NPT Review Conference agenda.
On 10 March the CD returned to discussions of NSAs. Official statements indicated clear international support for the creation of a legally binding agreement. Ambassador Dell Higgie of New Zealand encouraged consideration of an Irish proposal presented on 10 February which encouraged the creation of NSAs for NPT-compliant states. NWFZs were also discussed, particularly as Egypt urged more support from the international community in preparation for the Middle East NWFZ summit planned for 2012. During the latter part of 2011, discussion of NSAs in meetings of the CD was limited as the second and third sessions of the year were unable to reach agreement on a program of work. However, the official statements of many countries supported continued work on NSAs.
On 13 September, Nigeria presented a working paper on behalf of the G-21 on NSAs (CD/1924). The working paper reaffirmed the urgent need for a universal, unconditional and legally-binding instrument to assure NNWS against the use or threat of use of nuclear weapons. Moreover, the response of the nuclear-weapon States in UNSC resolutions 255 and 984 was “considered incomplete, partial and conditional by the non-nuclear-weapon States”.
In the General Assembly First Committee session in October, many countries’ official statements emphasized the importance of NSAs, including strong support from the New Agenda Coalition and the Non-Aligned Movement. On 14 October, the First Committee adopted draft resolution A/C.1/66/L.25 on the “Conclusion of effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.”
During the meetings of the CD, discussion of NSAs was limited as the body was unable to reach agreement on a program of work. Though several states expressed support for the negotiation of legally binding NSAs, no progress was made on the issue.
In April, the United States pledged in its Nuclear Posture Review not to “use or threaten to use nuclear weapons against non-nuclear weapons states that are party to the NPT and in compliance with their nuclear non-proliferation obligations,” marking a shift from previous U.S. reservations on use of nuclear weapons in response to a biological or chemical weapons attack.
During the 2010 NPT Review Conference in May, NSAs were the focus of significant debate, often conducted in tandem with conversations around nuclear-weapon-free zones. In their working papers, several delegation and groups of states called for the negotiation of legally binding NSAs or strengthening the existing ones, particularly the Non-Aligned Movement, the New Agenda Coalition, Iran, and Australia and Japan. The NWS emphasized their existing security assurances and the importance of NSAs in the context of NWFZs.
The Final Document of the NPT Review Conference in May established an action plan on nuclear disarmament that specifically addressed NSAs. Action 7 calls upon the CD to begin discussions of an internationally binding legal framework for NSAs, and Action 9 encourages the use of NSAs associated with NWFZs.
On 8 December 2010, the UN General Assembly adopted resolution 65/43 on the conclusion of effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons. The resolution encouraged all states, particularly NWS, to work actively to create a common approach to NSAs, particularly towards an international legally binding instrument. UN General Assembly also passed resolution 65/72 that day, encouraging NWSs to respect their existing security assurance commitments.
Iran submitted a working paper on NSAs to the NPT PrepCom proposing that the 2010 Review Conference “establish an ad hoc committee to work on a draft of a legally binding instrument on the illegality of nuclear weapons and the provision of security assurances by the five nuclear-weapon States to non-nuclear weapon States parties to the Treaty, and to submit the draft of the legal instrument to the  Review Conference for consideration and adoption.”
On 26 May, the CD adopted a program of work for the first time in a decade. The work plan established several working groups, including one entitled “Effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.” This working group was charged with discussing and forming recommendations regarding NSAs “not excluding those related to an internationally legally binding instrument.”
On 24 September, the UN Security Council passed Resolution 1887. This resolution recalls the statements made by the five NWS noted in Resolution 984 (1995). In these statements, the NWS gave harmonized, but in some cases, qualified security assurances to all NNWS party to the NPT.
The UN General Assembly adopted resolution 64/27 which noted that no members of the Conference in Disarmament objected in principle to a legally binding instrument on NSAs and appealed to all States to work towards a “common formula.” For the first time since 2005, the United States abstained from voting rather than be the only country to oppose the resolution outright.
During the NPT PrepCom, security assurances were addressed, although typically in an indirect manner. Most countries referred to NSAs in the context of nuclear-weapon-free-zones (NWFZs) or in relation to nuclear postures. This included addressing the military doctrine of preemptive action by a NWS if vital interests were threatened by biological, chemical and perhaps even overwhelming conventional forces.
Maintaining their past positions, the NWS continued to affirm UNSC Resolution 984 (1995) and recognized the protocols of the NWFZs. On the other side, the NAM continued its call for multilateral negotiations on a legally binding treaty that would provide security guarantees to all NNWS. The NAM also called for a subsidiary body on security assurances to be created at the 2010 NPT Review Conference.
Several statements explicitly referred to security assurances outside of the context of NWFZs. Indonesia, on behalf of the NAM called for the 2010 RevCon to “focus substantially on this crucial issue.” Ukraine, a non-NAM State, was unusually attentive to this issue. It offered to convene and “International Conference” on security assurances if it had support from various NPT delegations.
The NWS differed somewhat on their opinions. China stated it would consider a possible agreement or protocol in the context of the CD. China is the only NWS that maintains a “no use of nuclear weapons against NNWS” security assurance in addition to its no first use nuclear weapons policy. Russia, however, gave its support for the establishment of an ad hoc committee on NSAs in the CD “with a negotiating mandate.”
At the Preparatory Committee meeting for the 2010 NPT Review Conference, four working papers were presented regarding legally binding security assurances. These working papers were presented by Canada, China, Italy and the Non-Aligned Movement (NAM).
The UN General Assembly adopted resolution 62/19 on the “conclusion of effective international arrangements to assure non-nuclear-weapon States against the use or threat of use of nuclear weapons.”
The joint resolution for NSAs was again circulated at the UN General Assembly. NATO and the European Union continued to abstain from the resolution. In contrast to previous years, the United States changed its position to become the only State voting in opposition. In May Acting Assistant Secretary of State Stephen Rademaker told the UN Conference on Disarmament that the United States “sees no need at this time, however, for the negotiation of new multilateral agreements on…negative security assurances.”
Iran submitted a working paper (WP.49) to the NPT Review Conference proposing that the conference establish an ad hoc committee to draft a legally binding instrument and affirm that pending its completion, a new UN Security Council resolution underlining unqualified NSAs would “enhance regional and international peace and security.” As the RevCon failed to adopt a final document, no progress was made regarding consensus language on NSAs.
Brazil, Canada, Kenya, Mexico, New Zealand and Sweden presented a joint resolution to the UN General Assembly that promoted the creation of four CD Ad Hoc Committees to discuss four priority issues. Among these issues was the establishment of internationally binding security assurances.
Under the Six-Party talks in 2005, the Bush administration offered negative security assurances to North Korea (DPRK). In the fourth round of the Six-Party talks the United States put in writing that is has “no intention to attack or invade the DPRK with nuclear or conventional weapons.” However, at this point in time North Korea was uninterested in the security assurances offered by the United States due to Kim Jong Il’s desire for a more fundamental guarantee of his regime’s survival.
During the NPT PrepCom, the call for negative security assurances was reiterated by many of the NNWS, particularly from the NAM countries. These countries called for specific recommendations regarding “legally binding security assurances by the five nuclear-weapon-states” for the 2005 RevCon. All of the NWS except China strongly opposed the idea of extending NSAs to a global, legally binding treaty.
During the meeting of the heads of state of the Non-aligned Movement (NAM) in Kuala Lumpur, concern was raised over the possibility of the creation of new types of nuclear weapons, stemming from the U.S. Nuclear Posture Review released in 2001. The NAM heads of State declared that “pending the total elimination of nuclear weapons, efforts to conclude a universal, unconditional, and legally binding instrument on security assurances should be pursued as a matter of urgency, and that legally binding security assurances to NNWS parties to the NPT would strengthen the regime.” The NAM emphasized the necessity for the NPT to address the issue of NSAs during its PrepCom.
The New Agenda Coalition submitted a working paper (WP.11) to the second session of the NPT PrepCom which included a “Draft [Protocol][Agreement] on the Prohibition of the Use or Threat of Use of Nuclear Weapons against Non-Nuclear-Weapon States Parties to the Treaty on the Non-Proliferation of Nuclear Weapons.” The paper noted that an internationally legally binding instrument would need to contain “provisions on the mandatory actions to be undertaken by the Security Council where a beneficiary of the security assurances are the subject of a threat of use or use of nuclear weapons,” but Article III of the draft instrument offered only vague language taken from UNSCR 984 (1995).
In February, U.S. Department of State spokesperson Richard Boucher declared that “we will do whatever is necessary to deter the use of weapons of mass destruction against the United States, its allies, and its interests. If a weapon of mass destruction is used against the United States or its allies, we will not rule out any specific type of military response.” That following September, National Security Presidential Directive 17 took a more substantial stance regarding nuclear retaliation to the use of WMD an official U.S. policy. Leaked portions of the directive stated “the United States will continue to make clear that it reserves the right to respond with overwhelming force—including potentially nuclear weapons—to the use of WMD against the United States, our forces abroad, and friends and allies.”
With the events that occurred in New York on 11 September, the United States began to back away from its previous position on negative security assurances.
After the release of the new U.S. Nuclear Posture Review (NPR), many of the non-nuclear weapon States voiced concerns. The new NPR included contingencies for the possible use of nuclear weapons against certain non-nuclear weapon States under particular circumstances. In addition, the U.S. Congress approved funding for studies on the development of “robust nuclear earth penetrators” and for the possible development of mini-nukes. This funding approval signaled U.S. withdrawal from the “Spratt-Furse” ban on low-yield nuclear weapons. These actions raised strong concerns regarding the future of binding NSAs, particularly among the NAM states.
The statements made in the Nuclear Posture Review and National Defense Strategy regarding the possible (preemptive) use of nuclear weapons against NNWS reneges on the previous unilateral extension of negative security assurances from the United States. By backtracking on the pledges made in 1995 and 2000, the United States pushed the NNWS to pursue an internationally legally binding treaty to make the security assurances more concrete.
Negative security assurances were a primary point of discussion throughout the 2000 NPT Review Conference. In the preparatory phases several proposals were made by Myanmar and South Africa regarding the need to provide comprehensive and unconditional NSAs to the NNWS. The proposal made by South Africa stressed that the negotiations on legally binding security assurances should take place within the context of the Treaty.
The final document of the 2000 NPT RevCon made no reference to the possibility of an international treaty on negative security assurances. It did, however, reaffirm the role of the NPT as a forum for dealing with issues regarding NSAs and called on the PrepCom for the 2005 RevCon to make recommendations on the issue.
During the NPT Review and Extension Conference, the five NPT nuclear weapon states (NWS) reiterated unilateral negative security assurances to the non-nuclear weapon states (NNWS). These unilateral declarations of security assurances are contained in Security Council documents S/1995/261, S/1995/262, S/1995/263, S/1995/264, S/1995/265.
These assurances are not legally binding, and with the exception of China, which maintains a strict no-first-use policy, the assurances do not apply “in the case of an invasion or any other attack on the (NWS), its territories, its armed forces or other troops, its allies, or on a State towards which it has a security commitment, carried out or sustained by such a nonnuclear-weapon State in association or alliance with a nuclear-weapon State.”
The UN Security Council unanimously adopted Resolution 984 (1995), which recognized “the legitimate interest of [NPT NNWS] to receive security assurances” and noted “with appreciation” the non-binding unilateral pledges assurances” and noted “with appreciation” the non-binding unilateral pledges.