“The Arms Control Association and all of the staff I've worked with over the years … have this ability to speak truth to power in a wide variety of venues.”
– Marylia Kelley
Tri-Valley Communities Against a Radioactive Environment
June 2, 2022
Nuclear Security, Export Controls and Counterproliferation

The Australia Group at a Glance

March 2021

Contact: Daryl Kimball, executive director, (202) 463-8270 x107

Established in 1985, the Australia Group is a voluntary, informal, export-control arrangement through which 42 countries, as well as the European Union, coordinate their national export controls to limit the supply of chemicals and biological agents-as well as related equipment, technologies, and knowledge-to countries and nonstate entities suspected of pursuing chemical or biological weapons (CBW) capabilities.1 All participants are members of the 1997 Chemical Weapons Convention (CWC) and the 1972 Biological Weapons Convention (BWC) and have stated that they view the Australia Group as a practical way to uphold the core purpose of these accords: preventing the spread of chemical and biological weapons.

Citing the use of chemical weapons during the Iran-Iraq war, the Australian government proposed creating the group in April 1985 as a means of uniting 15 countries that had independently established national controls on chemical weapons-related exports. At the first meeting in June 1985, the Australia Group initially focused on chemical weapons but by 1990 had extended its activities to include biological weapons. Although the group has traditionally aimed to prevent states from acquiring CBW-related materials, it decided at its June 2002 meeting to also address the flow of CBW capabilities to nonstate actors, such as terrorists.

The Australia Group establishes "control lists," and its members are expected to deny export license requests for items on the lists when there is a concern that the items might be used in a CBW program. Each year members meet in Paris to coordinate these export control policies, discuss possible revisions to the common control lists, and share intelligence about global CBW proliferation and export denials. The group has no charter or constitution, and each country uses its own discretion when implementing national export controls, relying on the group's lists as a baseline but often creating stricter controls than suggested by the group. Sensitive items on these control lists can be divided into five categories:

  • Chemical weapons precursors-chemicals used in the production of chemical weapons.
  • Dual-use chemical manufacturing facilities, equipment, and related technology-items that can be used either for civilian purposes or for chemical weapons production, such as reactors, storage tanks, pumps, and valves.
  • Biological agents-disease-causing microorganisms, whether natural or genetically modified, such as smallpox, Marburg, foot-and-mouth disease, and anthrax.
  • Toxins-poisonous substances either made by living organisms or produced synthetically that adversely affect humans, animals, or plants, such as botulinum toxin and ricin.
  • Dual-use biological equipment-items that can be used for both peaceful research and biological weapons production, such as fermenters, containment facilities, freeze-drying equipment, and aerosol testing chambers.

As with all other decisions, the Australia Group accepts new members only by consensus. Countries wishing to gain membership to the group must meet certain criteria, including proven compliance with the CWC and the BWC, and an established, effective national export control and enforcement mechanism for all the items on the group's control lists. In deciding whether to accept new members, each current member also weighs its willingness to share intelligence with the applicant country. Nonparticipating states complain that the criteria for membership are excessively strict and that denying a country membership implicitly accuses that applicant of pursuing chemical or biological weapons.

Nonmembers have also questioned the Australia Group's relationship to the CWC and BWC. Countries in the Non-Aligned Movement (NAM), for instance, have repeatedly asserted that they already made legally binding commitments not to acquire CBW by signing the biological and chemical weapons conventions, and that the Australia Group is at odds with the BWC provision for the "fullest possible technical exchange" for the advancement of peaceful scientific endeavors. Participants of the Australia Group, however, maintain that the group complements CWC and the BWC and serves the same goals. A U.S. State Department official explained that "the Australia Group offers another layer of control, but one-in the U.S.'s view-that is consistent with the U.S.'s obligations under the chemical and biological weapons treaties."2

At their June 2002 meeting, the members unanimously decided to adopt a set of formal, but not legally binding, guidelines outlining criteria for evaluating export requests and reaffirming the value of sharing intelligence about CBW proliferation. The two key provisions in these guidelines were a "no undercut" agreement and a "catch all" requirement. In the no-undercut provision, members pledged not to approve a particular export to a specific country that another member had previously denied without first consulting with that member. The catch-all provision requires member countries to be able to halt the transfer of any export, regardless of whether it appears on the group's control lists, if an importer might use it in a chemical or biological weapons program. This provision further stipulates that exporters in member states notify their governments if they suspect that an importer intends to use any import for CBW development.

In response to heightened concerns about chemical and biological terrorism, the group also decided in June 2002 to control the spread of technology by "intangible means," prohibiting the transmission of CBW technologies by e-mail, phone, or fax. For instance, with controls on intangible technology transfers, a company could be required to obtain government authorization before faxing abroad a "cookbook" for growth media that could be used in a biological weapons program.

At the June 2012 plenary meeting, the group agreed to amend the guidelines in order to enhance controls on brokering services and continued reviewing the proliferation risks of new and emerging technologies, particularly in the area of nanotechnology.

Although the effectiveness of the Australia Group is difficult to gauge definitively, the 42 member countries assert that the regime acts as an impediment to CBW proliferation by working to ensure that industries in member nations do not, either inadvertently or intentionally, assist states or groups seeking to develop CBW capabilities.

  1. The 42 states participating in the Australia Group are Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, India, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Malta, Mexico, the Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, South Korea, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom, and the United States. The European Union also participates. Several other countries, including Russia and China, have national export controls for some, but not all, of the items on the group's lists.
  2. Quoted in Lois R. Ember, "Stemming the Tide," Chemical and Engineering News, July 15, 2002, p. 28.
Chemical/Biological Arms Control

The Wassenaar Arrangement at a Glance

February 2022

Contact: Daryl KimballExecutive Director, (202) 463-8270 x107


The Wassenaar Arrangement, formally established in July 1996, is a voluntary export control regime whose 42 members [1] exchange information on transfers of conventional weapons and dual-use goods and technologies. Through such exchanges, Wassenaar aims to promote "greater responsibility" among its members in exports of weapons and dual-use goods and to prevent "destabilizing accumulations." Unlike its predecessor, the Cold War-era Coordinating Committee for Multilateral Export Controls (COCOM), which was created to restrict exports to the former Soviet Union and Eastern bloc, Wassenaar is not targeted at any region or group of states, but rather at "states of concern" to members. Wassenaar members also lack veto authority over other member's proposed exports, a power that COCOM members exercised.

To promote transparency, Wassenaar calls on states to make a series of voluntary information exchanges and notifications on their export activities related to weapons and items appearing on the arrangement's two control lists.

For the Munitions List (Conventional Weapons):

Every six months, members exchange information on deliveries of conventional arms to non-Wassenaar members that fall under eight broad weapon categories: battle tanks, armored combat vehicles (ACVs), large-caliber artillery, military aircraft/unmanned aerial vehicles, military and attack helicopters, warships, missiles or missile systems, and small arms and light weapons. Members added the final category in December 2003 after years of debate. The ACV, aircraft, and helicopter categories include models designed to perform reconnaissance or conduct command of troops missions.

For the Dual-Use Goods and Technologies List:

Tier 1: Basic Items

Twice per year, members exchange information on all export licenses denied on proposed transfers to non-Wassenaar members.

Tier 2: Sensitive Items and its subset of Very Sensitive Items

  • Within 60 days, members are requested to notify the Wassenaar Secretariat of any export licenses denied on proposed transfers to non-Wassenaar members.
  • Twice per year, members exchange information on all export licenses issued or transfers made to non-Wassenaar members.
  • For the subset of Very Sensitive items, such as stealth technology materials and advanced radar, members are called on to "exert extreme vigilance" in exports.
  • Within 60 days, members are requested to notify the Wassenaar Secretariat of any export license approvals of transactions that are "essentially identical" to transactions that another Wassenaar member denied within the past three years. Wassenaar members are not obligated to deny transfers previously denied by others.

Although Wassenaar has overcome a great deal of growing pains, problems persist. Foremost among the arrangement's difficulties is that members continue to be divided over Wassenaar's scope, primarily whether the arrangement should become more than just a body for exchanging and collecting information. Because Wassenaar operates by consensus, a single country can block any proposal. In earlier years, a few members consistently refused to fully participate in voluntary information exchanges and notifications on dual-use goods, though participation has reportedly improved.[2] In addition, there is no consensus among members on which countries are "states of concern" or what constitutes a "destabilizing" transfer. Another limiting factor is that some major arms exporters, such as Belarus, China, and Israel are not members.

During the arrangement's years of operation, Wassenaar members have reaffirmed their commitment to preventing terrorist groups and individuals from acquiring conventional arms and dual-use goods and technologies, agreed to "exercise maximum restraint" in exports to the Great Lakes region of Africa, gradually expanded the types of weapons exports that information is exchanged upon, and agreed on the importance of "responsible export policies" on small arms and light weapons. At its December 1998 plenary meeting, the members approved a paper of non-binding criteria to help governments determine whether potential arms exports could lead to destabilizing accumulations.[3] Wassenaar members have also agreed on non-binding criteria to guide exports of shoulder-fired, surface-to-air missiles, formally referred to as man-portable air defense Systems (MANPADS), and endorsed voluntary "best practices" for disposing of surplus military equipment, enforcing national export controls, and controlling Very Sensitive dual-use exports. They have also approved non-binding criteria to guide exports of small arms and light weapons, agreed to exercise greater control on arms brokers, and committed to better regulate exports of dual-use goods purchased by recipients subject to arms embargos if the item is intended for a military end-use.


1. The 42 participating states in the Wassenaar Arrangement are Argentina, Australia, Austria, Belgium, Bulgaria, Canada, Croatia, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, India, Ireland, Italy, Japan, Latvia, Lithuania, Luxembourg, Malta, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russia, Slovakia, Slovenia, South Africa, South Korea, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom, and the United States.

2. Wassenaar members agreed that all information exchanges, notifications, and Wassenaar discussions be kept confidential.

3. The Arms Control Association can provide copies upon request.

Conventional Arms Issues

UN Security Council Resolution 1540 At a Glance

February 2021

Contact: Kelsey Davenport, Director for Nonproliferation Policy, (202) 463-8270 x102

On April 28, 2004, the UN Security Council unanimously voted to adopt Resolution 1540, a measure aimed at preventing non-state actors from acquiring nuclear, biological, and chemical weapons, their means of delivery, and related materials. The resolution filled a gap in international law by addressing the risk that terrorists might obtain, proliferate, or use weapons of mass destruction.

Adopted under Chapter VII of the UN Charter, UNSCR 1540 formally establishes the proliferation and possession of WMD by non-state actors as “a threat to international peace and security.” The resolution mirrors the approach taken under UNSCR 1373 in 2001, which required all countries to adopt national counter-terrorism laws, and imposes legally binding obligations on all states to adopt "appropriate effective" measures to prevent the proliferation of WMD to non-state actors.

The resolution includes three primary obligations:

  1. All States are prohibited from providing any form of support to non-state actors seeking to acquire weapons of mass destruction, related materials, or their means of delivery.
  2. All States must adopt and enforce laws criminalizing the possession and acquisition of such items by non-state actors, as well as efforts to assist or finance their acquisition.
  3. All States must adopt and enforce domestic controls over nuclear, chemical, and biological weapons, their means of delivery, and related materials, in order to prevent their proliferation.

UNSCR 1540 also emphasizes the importance of maintaining and promoting existing non-proliferation multilateral agreements and acknowledges that the resolution does not interfere with state obligations under such treaties.

It further recognizes that some countries may require assistance to meet the national implementation obligations of the resolution. As such, the resolution calls on states to make assistance available to countries in need if they are in a position to do so.

The council established a committee to oversee the implementation of the resolution, initially for a period of two years. Comprised of the council’s 15 members and assisted by a panel of experts, the 1540 Committee is tasked with providing awareness of the resolution and its requirements, matching assistance requests with offers, and assessing the status of implementation. States were required to report to the Committee on the actions they have taken or plan to take in order to implement the resolution within 6 months of UNSCR 1540’s adoption, and the council has encouraged subsequent reports to provide additional information.

Despite its aim of preventing nuclear, chemical, and biological terrorism, resolution 1540 initially met with some resistance within the UN Security Council, with critics stressing that the resolution focused solely on nonproliferation without adequate emphasis on disarmament.  There was additional concern that the UN might use UNSCR 1540 to justify sanctions and other forms of coercion for countries that did not adequately comply with the resolution.

These worries were generally alleviated, as evidenced by the UN Security Council's unanimous vote to extend UNSCR 1540’s mandate, first for two years in 2006 under resolution 1673, then for another three years in 2008 under resolution 1810. In April 2011, the UN Security Council passed resolution 1977, extending the mandate a third time, for a period of ten years. UNSCR 1977 reaffirmed the Security Council’s commitment to resolution 1540, and further emphasized cooperation with international, regional, and sub-regional organizations. It also addressed existing concerns among Council members regarding equal regional representation within the 1540 Committee. In December 2016, the UN Security Council adopted Resolution 2325 encouraging states to strengthen their implementation of Resolution 1540. 

 In addition to annual reviews, the 1540 committee conducts comprehensive reviews every five years on the implementation of Resolution 1540. So far, two comprehensive reviews have been completed, one in 2009 and another in 2016. The 2016 comprehensive final review found that while the number of implementation measures states have taken since 2011 has increased, for many states, gaps in the securing of relevant materials remain. The report also noted that the risk of proliferation to non-state actors is increasing due to rapid advances in science, technology, and international commerce. 

While the committee was scheduled to produce another comprehensive review in December 2020, this process was delayed due to COVID-19. Open consultations with member states, international organizations, and civil society groups are scheduled to resume in 2021 ahead of the renewal of the committee’s mandate on April 25, 2021.

Strategic Arms Control and Policy

Country Resources:

The Nuclear Suppliers Group (NSG) at a Glance

March 2022

Contacts: Daryl Kimball, Executive Director, (202) 463-8270 x107; Kelsey Davenport, Director for Nonproliferation Policy, (202) 463-8270 x102

Established in 1975, the Nuclear Suppliers Group (NSG) is comprised of 48 states that have voluntarily agreed to coordinate their export controls to non-nuclear-weapon states. The NSG governs the transfers of civilian nuclear material and nuclear-related equipment and technology. The participants are: Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Kazakhstan, Latvia, Lithuania, Luxembourg, Malta, Mexico, Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, South Africa, South Korea, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom, and the United States.

The NSG aims to prevent nuclear exports for commercial and peaceful purposes from being used to make nuclear weapons. In order to ensure that their nuclear imports are not used to develop weapons, NSG members are expected to forgo nuclear trade with governments that do not subject themselves to confidence-building international measures and inspections. The NSG has two sets of Guidelines listing the specific nuclear materials, equipment, and technologies that are subject to export controls.



Negotiated in 1968, the nuclear Nonproliferation Treaty (NPT) granted non-nuclear-weapon states access to nuclear materials and technology for strictly peaceful purposes.

Recognizing peaceful nuclear programs could turn into weapons programs, several NPT nuclear supplier states sought to determine the conditions for sharing specific equipment and materials with non-nuclear-weapon states. In 1971, these supplier states formed the Zangger Committee in order to require states outside the NPT to institute International Atomic Energy Agency (IAEA) safeguards before importing certain items that could be used to pursue nuclear weapons—referred to as the "Trigger List."

India's explosion of a nuclear device in 1974 reaffirmed the fact that nuclear materials and technologies acquired under the guise of peaceful purposes could be diverted to build weapons. In response to India's action, several Zangger Committee members, along with France—who was not a member of the NPT at that time—established the NSG to further regulate nuclear-related exports. The NSG also added supplemental technologies to the original Zangger Committee's "Trigger List," becoming Part I of the NSG Guidelines. In addition, NSG members agreed to apply their trade restrictions to all states, not just those outside the NPT.


Guidelines and Operation

The NSG Guidelines require that importing states provide assurances to NSG members that proposed deals will not contribute to the creation of nuclear weapons. Potential recipients are also expected to have physical security measures in place to prevent theft or unauthorized use of their imports and to promise that nuclear materials and information will not be transferred to a third party without the explicit permission of the original exporter. In addition, final destinations for any transfer must have IAEA safeguards in place. The IAEA is charged with verifying that non-nuclear-weapon states are not illicitly pursuing nuclear weapons. To prevent nuclear material or technology from being stolen or misappropriated for weapons, IAEA safeguards include inspections, remote monitoring, seals, and other measures.

The Guidelines are comprised of two parts, each created in response to significant proliferation events that highlighted shortcomings in the export control systems.

Part I lists materials and technology designed specifically for nuclear use. These include fissile materials, nuclear reactors and equipment, and reprocessing and enrichment equipment. First published in 1978, Part I responded to India's 1974 diversion of nuclear imports for supposedly peaceful purposes to conduct a nuclear explosion. To be eligible for importing Part I items from an NSG member, states must have comprehensive IAEA safeguards covering all their nuclear activities and facilities. In the case of Part II goods, IAEA safeguards are only required for the specific nuclear activity or facility designated for the import.

Part II identifies dual-use goods; non-nuclear items with legitimate civilian applications that can also be used to develop weapons. Machine tools and lasers are two types of dual-use goods. NSG members adopted Part II in 1992 after discovering how close Iraq came to realizing its nuclear weapons ambitions. Iraq had illicitly employed dual-use imports in a covert nuclear weapons program before the 1991 Persian Gulf War.

At a May 2004 meeting, NSG members adopted a "catch-all" mechanism, which authorizes members to block any export suspected to be destined to a nuclear weapons program even if the export does not appear on one of the control lists.

Because the regime is voluntary, NSG members may ultimately make a political calculation to proceed with a transfer that violates the guidelines. For instance, Russia transferred nuclear fuel to India in January 2001 even though 32 of 34 NSG members earlier declared that the shipment would contradict Russia's NSG commitments.

Members are supposed to report their export denials to each other so potential proliferators cannot approach several suppliers with the same request and receive different responses. NSG states are expected to refrain from making exports identical or similar to those denied by other members.

In 2008, the NSG agreed to exempt India from its requirement that recipient countries must have comprehensive IAEA safeguards covering all nuclear activities. The United States pressed for a three-year exemption to allow nuclear trade with India, but some NSG members were reluctant to agree to such a reversal. The waiver commits each NSG member to regularly inform the group of approved transfers to India and invites each country to share information on their bilateral nuclear cooperation agreements with India.

As part of the organization, NSG members periodically review the Guidelines to add new items that pose proliferation risks or to eliminate goods that no longer require special trade controls. An annual plenary, which is chaired on a rotating basis among members, is held to discuss the regime's operation, including possible changes to the Guidelines. All NSG decisions are made by consensus. Members also participate in regular meetings of separate standing bodies—the Dual-Use Consultations and the Joint Information Exchange—devoted to reviewing Part II of the Guidelines and exchanging pertinent information.

The Permanent Mission of Japan to the International Organisations in Vienna serves as the NSG point of contact. It receives and distributes NSG documents, schedules meetings, and assists with other administrative work.



Any state that conducts exports appearing on the Guidelines may apply for NSG membership. A potential member is evaluated on its proliferation record for national export controls and adherence to international nonproliferation treaties and agreements. All existing members must approve an applicant for admittance to the regime. There are several countries with nuclear programs outside the NSG, most notably India, Israel, Pakistan, and North Korea.

In recent years, India has advanced its bid to join the NSG. Although President Barack Obama  expressed support for India’s membership to the NSG in 2010, the group remains divided, in part because, as a non-state-party to the NPT, India doesn’t meet a core criterion for membership.

At the June 2016 NSG meeting, the United States and India pushed for acceptance of India’s bid for membership. All of the participating states, except for China, support allowing  India to join the NSG without signing the NPT. China noted that other non-NPT states in addition to India had expressed desire in joining the NSG, and therefore India should not receive an exclusive exemption. As China’s ambassador to Vienna, Shi Zhongjun, explained in June 2016, as “NPT membership constitutes one of the prerequisite factors for consideration of NSG participation, [m]ore discussions are needed before the Group is in a position to review…participation by any specific non-NPT state at the meetings of the Group.” China’s aim is to define non-discriminatory guidelines for membership that would remove the possibility of political bias.

In response to India’s bid, Pakistan also expressed a desire to join the NSG. On May 20, 2016, Pakistan’s ambassador sent a letter to formally apply for NSG membership, arguing that it also has the credentials to join.

India has since continued its bid for NSG membership, citing a commitment to enhancing its nuclear power capacity and its need for raw nuclear materials.

Nuclear/Ballistic Missile Nonproliferation

The Missile Technology Control Regime at a Glance

March 2021

Contact: Kelsey Davenport, Director for Nonproliferation Policy, (202) 463-8270 x102

The Missile Technology Control Regime Guidelines and Annex

A Russian Topol-M intercontinental ballistic missile launcher drives through the Red Square in Moscow, on May 9, 2014, during a Victory Day parade. (Photo: Kirill Kudryavtsev/AFP/Getty Images)Established in April 1987, the voluntary Missile Technology Control Regime (MTCR) aims to limit the spread of ballistic missiles and other unmanned delivery systems that could be used for chemical, biological, and nuclear attacks. The regime urges its 35 members,1 which include most of the world's key missile manufacturers, to restrict their exports of missiles and related technologies capable of carrying a 500-kilogram payload at least 300 kilometers or delivering any type of weapon of mass destruction.2

Since its inception, the MTCR has been credited with slowing or stopping several missile programs by making it difficult for prospective buyers to get what they want or stigmatizing certain activities and programs. Argentina, Egypt, and Iraq abandoned their joint Condor II ballistic missile program. Brazil, South Africa, South Korea, and Taiwan also shelved or eliminated missile or space launch vehicle programs. Some Eastern European countries, such as Poland and the Czech Republic, destroyed their ballistic missiles, in part, to better their chances of joining the MTCR.3 The regime has further hampered Libyan and Syrian missile efforts.

Yet, the regime has its limitations. Iran, India, North Korea, and Pakistan continue to advance their missile programs. All four countries, with varying degrees of foreign assistance, have deployed medium-range ballistic missiles that can travel more than 1,000 kilometers and are exploring missiles with much greater ranges. India is testing missiles in the intercontinental range. These countries, which are not MTCR members except India, are also becoming sellers rather than simply buyers on the global arms market. North Korea, for example, is viewed as the primary source of ballistic missile proliferation in the world today. Iran has supplied missile production items to Syria.

In July 2020, the United States announced that it would reinterpret its implementation of Category I controls with regards to drones that travel at speeds below 800 kilometers per hour. This change lifts the strict Category I export restriction on several American-made drones like the Predator and Reaper.

How the MTCR Works

Each MTCR member is supposed to establish national export control policies for ballistic missiles, cruise missiles, unmanned aerial vehicles, space launch vehicles, drones, remotely piloted vehicles, sounding rockets, and underlying components and technologies that appear on the regime's Material and Technology Annex. Members can add items to or subtract them from the annex through consensus decisions.

The annex is divided into two separate groupings of items, Category I and Category II. Category I includes complete missiles, rockets, and unmanned air vehicle systems; major sub-systems; and production facilities. Specialized materials, technologies, propellants, and sub-components for missiles and rockets comprise Category II.

Potential exports of Category I and II items are to be evaluated on a case-by-case basis. Approval for Category I exports is supposed to be rare. The regime's guidelines, which set out criteria for weighing possible exports, instruct members that "there will be a strong presumption to deny" Category I transfers. No exports of production facilities are to be authorized. MTCR restrictions for Category II exports are less severe, largely because many items in the category also have civilian uses. Members, however, are still asked to exercise caution in making such deals. No member can veto another's exports.

The MTCR identifies five factors that members should take into account when evaluating a possible export of controlled items:

  • Whether the intended recipient is pursuing or has ambitions for acquiring weapons of mass destruction;
  • The purposes and capabilities of the intended recipient's missile and space programs;
  • The potential contribution the proposed transfer could make to the intended recipient's development of delivery systems for weapons of mass destruction;
  • The credibility of the intended recipient's stated purpose for the purchase; and
  • Whether the potential transfer conflicts with any multilateral treaty.

MTCR members are asked to obtain an assurance from the intended recipient that it will only use the export for the purpose claimed when requesting the deal. Members are also to secure a pledge from the intended recipient that it will not transfer the requested item or any replicas or derivatives to a third party without permission.

Because the regime is voluntary and the decision to export is the sole responsibility of each member, the MTCR has no penalties for transfers of controlled items. However, U.S. law mandates that Washington sanction entities-individuals, companies, or governments (whether they are MTCR members or not)-exporting MTCR-controlled items to certain countries identified as proliferators or potential threats to U.S. security. Sanctions may also be levied if the United States judges the transfer contrary to the MTCR. Typically, Washington prohibits the charged entity from signing contracts, receiving aid, or buying arms from the U.S. government for a period of two years. Sometimes the penalties can be imposed for longer lengths of time or extended to commercial imports and exports as well.

Outside the MTCR

Several countries have pledged to abide by the MTCR without joining it. Israel, Romania, and the Slovak Republic have all committed to maintaining export controls consistent with the regime.

After several years of the U.S. curtailing its sale of missiles and missile technologies, China announced in November 2000 that it would not help other countries build ballistic missiles capable of delivering nuclear weapons. Beijing, which was a key contributor to Pakistan's missile development, and has in the past provided sensitive technology to countries like North Korea and Iran, also pledged that it would issue a comprehensive list of controlled items requiring government approval before export. That list, however, was not published until August 2002. In 2004, China applied for MTCR membership, and, at the time, voluntarily pledged to follow the regime's export control guidelines. Although China no longer sells complete missile systems and has tightened its export controls, its membership was rejected due to concerns that Chinese entities continued to provide sensitive technologies to countries developing ballistic missiles, such as North Korea.

In 2008 India voluntarily committed to following the MTCR export control guidelines, since that time the United States has been working to secure India's membership in the regime. India's announcement was made shortly before the Nuclear Suppliers Group granted an exemption to India. New Delhi continues to develop its own ballistic missile program. In June 2015, India formally applied for membership in the regime, but Italy blocked consensus on its application during the October 2015 plenary. Nine other countries applied as well in 2015, none of which were admitted into the regime. India was later admitted in June 2016. 

Hague Code of Conduct Against Ballistic Missile Proliferation

MTCR members spearheaded a voluntary November 2002 initiative, the Hague Code of Conduct Against Ballistic Missile Proliferation (formerly known as the International Code of Conduct Against Ballistic Missile Proliferation), calling on all countries to show greater restraint in their own development of ballistic missiles capable of delivering weapons of mass destruction and to reduce their existing missile arsenals if possible. The aim of the initiative is to establish a norm against missiles that could be armed with chemical, biological, or nuclear warheads. As part of the initiative, participating countries are to annually exchange information on their ballistic missile and space launch vehicle programs, as well as provide advance notice of any launches of ballistic missiles or space launch vehicles. The Hague Code of Conduct has 143 member states, including all MTCR members except Brazil. Brazil has expressed concerns about how the initiative might affect its space program.


1. MTCR members, followed by the year they joined the regime, are: Argentina (1993), Australia (1990), Austria (1991), Belgium (1990), Brazil (1995), Bulgaria (2004), Canada (1987), the Czech Republic (1998), Denmark (1990), Finland (1991), France (1987), Germany (1987), Greece (1992), Hungary (1993), Iceland (1993), India (2016), Ireland (1992), Italy (1987), Japan (1987), Luxembourg (1990), the Netherlands (1990), New Zealand (1991), Norway (1990), Poland (1998), Portugal (1992), Russia (1995), South Africa (1995), South Korea (2001) Spain (1990), Sweden (1991), Switzerland (1992), Turkey (1997), Ukraine (1998), the United Kingdom (1987), and the United States (1987).

2. Originally, the MTCR was limited to stopping the proliferation of nuclear-capable missiles, which was defined as a missile able to travel at least 300 kilometers with a 500-kilogram payload. Five hundred kilograms was considered the minimum weight of a first generation nuclear warhead, while 300 kilometers was believed to be the minimum distance needed to carry out a strategic strike. Members agreed in the summer of 1992 to expand the regime's objective to also apply to missiles and related technologies designed for chemical and biological weapons. That change took effect in January 1993. The move effectively tasked members with a making a more difficult and subjective assessment about an importer's intentions, as opposed to denying a specific capability (a missile able to deliver a 500-kilogram payload at least 300 kilometers), because many more missiles and unmanned delivery vehicles could be adapted to deliver lighter chemical and biological weapons payloads.

3. Prospective MTCR members must win consensus approval from existing members. U.S. policy is that new members that are not recognized nuclear-weapon states must eliminate or forgo ballistic missiles able to deliver a 500-kilogram payload at least 300 kilometers. The United States, however, made an exception in 1998 for Ukraine, permitting it to retain Scud missiles. Three years later, Washington also agreed to let South Korea develop missiles with ranges up to 300 kilometers to secure its membership in the MTCR. Seoul previously agreed in 1979 to limit its missile development to those with ranges less than 180 kilometers. South Korea was granted another extension in October 2012. Seoul and Washington reached an agreement allowing South Korea to extend the range of its ballistic missiles to 800 kilometers with a 500 kilogram payload. This extension will allow Seoul to target all of North Korea. South Korea tested a ballistic missile with a range of 500 km in June 2015 and announced in October 2015 that it would deploy systems with an 800 km range in 2017.

Nuclear/Ballistic Missile Nonproliferation

The Proliferation Security Initiative (PSI) At a Glance

March 2022

Contact: Kelsey Davenport, Director for Nonproliferation Policy, (202) 463-8270 x102

Updated: March 2022

The Proliferation Security Initiative (PSI) is a voluntary, multilateral effort initiated by U.S. President George W. Bush in May 2003 to strengthen the nonproliferation architecture. Specifically, PSI seeks to enhance interdiction capabilities and increase coordination between states to disrupt trade in weapons of mass destruction (WMD), delivery systems, and related materials.

Several factors motivated the Bush administration to create PSI. In the 2002 National Strategy to Combat Weapons of Mass Destruction Proliferation, the administration recognized the important role that interdicting technologies and materials plays in disrupting proliferation. The strategy concluded that “we must enhance the capabilities of our military, intelligence, technical, and law enforcement communities to prevent the movement of WMD materials, technology, and expertise to hostile states and terrorist organizations.”

The Bush administration also viewed PSI as responding to a gap made evident by the December 2002 So San incident. The So San was a North Korean ship carrying Scud missiles bound for Yemen when it was intercepted by Spanish authorities acting on intelligence provided by the United States. The United States and Spain, however, could not seize the missile parts because there was no legal basis to do so. The So Sanwas released and continued on to Yemen, after Yemenis authorities provided assurances that the country would not transfer the missiles to any third party.


PSI aims to disrupt and deter shipments of biological, chemical, and nuclear weapons, their means of delivery, and the illicit transfer of dual-use goods that could be used to produce such weapons. It also seeks to enhance cooperation between states to promote intelligence and information sharing about suspected shipments of proliferation concern.

Then-Undersecretary of State for Arms Control and International Security John Bolton indicated in November 2003 that participants would be targeting shipments to non-state actors or states pursing WMDs in violation of international law.

The original PSI member states emphasized that the initiative is “an activity not an organization,” thus it has never had a formal implementing body or secretariat. PSI also does not receive dedicated funding from participating states. An informal 21-member body, known as the Operational Experts Group (OEG), serves a coordinating function and plans exercises and activities.

The list of states that comprise the OEG is available here.

Principles and Participation:

Ten countries—Australia, France, Germany, Italy, Japan, the Netherlands, Poland, Portugal, Spain, and the United Kingdom—worked with the United States to shape the initiative and craft its interdiction principles.

In September 2003, the 11 original PSI participants released the Statement of Interdiction Principles, the non-binding document that lays out the mission of PSI and the expectations for membership. Any state can join PSI by endorsing the principles.

The principles call on PSI participants, as well as other countries, to not engage in WMD-related trade with countries of proliferation concern and to permit their own vessels and aircraft to be searched if suspected of transporting such goods.

The principles also include commitments to: 

  • develop measures to interdict transfers of WMDs, and related materials and technologies of proliferation concern,
  • strengthen national legal authorities and frameworks for interdictions,
  • adopt procedures for sharing information with other states about suspected proliferation activities, and
  • support interdiction efforts, including by negotiating ship boarding consent agreements and stopping and searching suspected shipments in territorial waters and airspaces.

As of 2019, 107 states have endorsed the Statement of Principles.

Legal Status: 

PSI does not create new law, but rather relies on existing international law to conduct interdictions in international waters or airspace. For example, a ship can be stopped in international waters if it is not flying a national flag or properly registered.

States can also conduct interdictions when directed to do so by UN Security Council resolutions adopted under Section VII of the UN Charter. For example, after the UN Security Council passed two resolutions on North Korea in 2017, a group of PSI participants issued a press releasein 2018 expressing support for the interdiction provisions in the resolutions. The press release also drew attention to the complimentary actions participating states are encouraged to take that support enforcement of the resolutions.

PSI participants are encouraged to develop their national laws and join international treaties that criminalize WMD related trafficking, such as the 2005 protocol to the Convention for the Suppression of Unlawful Acts Against the Safety of Maritime Navigation(SUA Convention). The SUA convention’s 2005 protocol prohibits maritime shipment of WMDs and related technologies outside of legitimate trade under the nuclear Nonproliferation Treaty and International Atomic Energy Agency safeguards. The protocol allows ships to be boarded, with the consent of the flag state, if they are suspected of carrying illicit cargo, thus strengthening the legal basis for interdictions.

PSI member states also seek to expand their legal authority to interdict shipments by signing bilateral boarding agreements with select countries to secure expedited processes or pre-approval for stopping and searching their ships at sea.

Activities and Meetings:

To build capacity and best practices, participating states can participate in exercises and workshops convened by PSI members. Between 2003-2018 more than 85 workshops and exercises were hosted by PSI member states. Some groups of states have taken the initiative to hold more regular activities designed to counter regional threats, including:

  • The Mediterranean Initiative: During PSI’s high-level political meeting in 2013, France and Germany proposed creating a dedicated channel to focus on challenges in the Mediterranean region. The objectives of the initiative are to discuss risks specific to region, strengthen cooperation amongst PSI and non-PSI stakeholders, and increase capacity. Activities have included seminars to discuss counter-proliferation strategies for the region, table-top exercises, and live exercises that include interdiction best practices.
  • The Asia-Pacific Exercise Rotation: Australia, Japan, New Zealand, South Korea, Singapore and the United States committed to rotate hosting yearly exercises focused on the Asia-Pacific region.

A list of PSI activities from 2003-2018 is available here.

On May 28, 2013, representatives from seventy-two PSI member states held a High Level Political Meeting in Warsaw on the 10th anniversary of the PSI’s formation. Attending states affirmed four joint statements pledging to conduct “more regular and robust” PSI exercises; promote international treaties criminalizing WMD-related trafficking; share expertise and resources to enhance interdiction capabilities; and to expand “the influence of the PSI globally through outreach to new states and the public.”

A mid-level meeting took place in Washington, DC in January 2016 that included representatives from 71 countries. Thomas Countryman, U.S. assistant secretary of state for international security and nonproliferation, said that participants discussed topics such as trends in proliferation, tactics that networks use to ship sensitive materials and technologies, and options to control proliferation financing. Countryman also said that countries shared expertise and resources that should contribute to building countries’ ability to carry out interdictions.


It is difficult to assess how effective the initiative has been since its inception in 2003. Given that PSI utilizes shared intelligence and interdictions may be conducted based off of multiple streams of information, successes are rarely credited directly to the initiative.

U.S. officials have acknowledged that PSI played an important role in a number of successful interdictions, including seizing centrifuge components that the A.Q. Khan network was shipping to Libya in 2003. In a June 2006 speech, then-Undersecretary of State Robert Joseph claimed that between April 2005 and April 2006 the United States had cooperated with other PSI participants on “roughly two dozen” occasions to prevent transfers of concern. Ulrik Federspiel, Denmark’s ambassador to the United States, asserted at a May 2005 event that “the shipment of missiles has fallen significantly in the lifetime of PSI.”

At a 2008 conference for PSI participants, the United States provided a briefing paper outlining five interdictions where PSI played a significant role.

  • February 2005: A European government denied an export license for coolers U.S. intelligence assessed were intended for Iran’s nuclear program.
  • November 2006: A state stopped the transfer for chromium-nickel steel plates to Iran that could have been used for that country’s ballistic missile program and returned the materials to the country of origin.
  • February 2007: Shared intelligence led authorities in a state to interdict U.S. origin equipment bound for Syria that could have been used for ballistic missile development.
  • April 2007: An Asian country stopped a shipment of sodium perchlorate, which can be used for making solid rocket motors, that was en route to Iran.
  • June 2007: A country denied overflight to a Syrian aircraft making a trip to North Korea based on shared intelligence that the cargo was carrying ballistic missile related components.


Nuclear/Ballistic Missile Nonproliferation

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