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Fact Sheet
Bureau of International Security and Nonproliferation
Washington, DC
May 22, 2008

Proliferation Security Initiative Frequently Asked Questions (FAQ)

Previous Version: 2005

The Fundamentals of the PSI

Question: What is the Proliferation Security Initiative (PSI)?

A: The Proliferation Security Initiative (PSI) is a global effort that aims to stop trafficking of weapons of mass destruction (WMD), their delivery systems, and related materials to and from states and non-state actors of proliferation concern. Launched by President Bush on May 31, 2003, U.S. involvement in the PSI stems from the U.S. National Strategy to Combat Weapons of Mass Destruction issued in December 2002. That strategy recognizes the need for more robust tools to stop proliferation of WMD around the world, and specifically identifies interdiction as an area where greater focus will be placed. Today, more than 90 countries around the world support the PSI.

The PSI is an innovative and proactive approach to preventing proliferation that relies on voluntary actions by states that are consistent with national legal authorities and relevant international law and frameworks. PSI participants use existing authorities -- national and international -- to put an end to WMD-related trafficking and take steps to strengthen those authorities as necessary. UN Security Council Resolution 1540, adopted unanimously by the Security Council, called on all states to take cooperative action to prevent trafficking in WMD. The PSI is a positive way to take such cooperative action.

In September 2003, PSI participants agreed to the PSI Statement of Interdiction Principles that identifies specific steps participants can take to effectively interdict WMD-related shipments and prevent proliferation. The PSI Principles also recognize the value in cooperative action and encourage participating countries to work together to apply intelligence, diplomatic, law enforcement, military, and other capabilities to prevent WMD-related transfers to states and non-state actors of proliferation concern.

PSI partners encourage all states to endorse the PSI, and to take the steps outlined in the Principles. Support for the PSI is an acknowledgment of the need for stronger measures to defeat proliferators through cooperation with other countries.

Question: What is the PSI Statement of Interdiction Principles?

A: The Statement of Interdiction Principles (SOP) was agreed by PSI participants on September 4, 2003. It identifies specific steps for effectively interdicting proliferation-related shipments and preventing proliferators from engaging in the proliferation trade. It serves as the basis for PSI participants’ deepening cooperation with each other.

While the Principles have been agreed, the PSI is a dynamic initiative. If countries have ideas that are not reflected in the SOP that would contribute to a more robust, effective initiative, we want to hear from them. In that way, the PSI is an initiative open to contributions from all states that want to support WMD interdiction efforts.

Question: What constitutes a "country of concern?" Would failure of a state to join a nonproliferation regime automatically qualify it as a state of concern?

A: Paragraph 1 of the PSI Statement of Interdiction Principles contains a definition of "states or non-state actors of proliferation concern." This definition says that, "states or non-state actors of proliferation concern generally refers to those countries or entities that the PSI participants involved establish should be subject to interdiction activities because they are engaged in proliferation through: (1) efforts to develop or acquire chemical, biological, or nuclear weapons and associated delivery systems; or (2) transfers (either selling, receiving, or facilitating) of WMD, their delivery systems, or related materials."

The basis for considering a state "of proliferation concern" is not whether or not a state has joined multilateral nonproliferation treaties or regimes.

Question: What is the definition of "good cause?"

A: Paragraph 4b of the SOP calls upon states to take specific actions “at their own initiative, or at the request and good cause shown by another state, to take action to board and search any vessel flying their flag in their internal waters or territorial seas, or areas beyond the territorial seas of any other state, that is reasonably suspected of transporting such cargoes to or from states or non-state actors of proliferation concern, and to seize such cargoes that are identified.”

In responding to such a request, each state will, of necessity, decide for itself whether the information provided by the requesting state warrants acceding to the request.

Question: How should states endorse the PSI Statement of Interdiction Principles?

A: The best way to endorse the PSI SOP is through a diplomatic note to a participating country, accompanied by a public statement of support.

Q. Has the PSI been successful?

A: The PSI is making WMD trafficking, to include delivery systems and other related material, increasingly difficult for proliferators. The PSI increases traffickers’ operational costs and the risks associated with trafficking prohibited items. This stems from such activities as the U.S. establishing PSI boarding agreements with key flag states (Panama, Liberia, Marshall Islands, Croatia, Cyprus, Belize, Malta and Mongolia) that facilitate maritime interdictions as well as from nations strengthening their national laws. Additionally, exercises have improved interoperability among PSI endorsers. Exercises also demonstrate the commitment of participants to the PSI Statement of Interdiction Principles, test national capabilities to conduct air, ground, and maritime interdictions, and increase understanding of PSI globally and within geographic regions. Future PSI goals include increasing the number of PSI endorsing states and pursuing industry cooperation to increase awareness and preclude unintentional impacts.

The results of our interdiction efforts must necessarily be kept in classified channels because of sensitive sources and methods. Quiet actions help us stay one step ahead of the proliferators and give them less insight into steps they can take to evade detection. The United States has worked successfully with multiple PSI partners in Europe, Asia and the Middle East to prevent transfers of equipment and materials to WMD and missile programs in countries of proliferation concern. For example, PSI cooperation has stopped the export to Iran’s missile program of controlled equipment and dual-use goods. One PSI partner has also stopped the export of heavy water-related equipment to Iran’s nuclear program.

Question: How Does the PSI Work?

A: The PSI works in three primary ways. First, it channels international commitment to stopping WMD-related proliferation by focusing on interdiction as a key component of a global counterproliferation strategy.

Second, the PSI provides participating countries with opportunities to improve national capabilities and strengthen authorities to conduct interdictions. A robust PSI exercise program allows participants to increase their interoperability, improve interdiction decision-making processes, and enhance the interdiction capacities and readiness of all participating states. In five years, PSI partners have sustained one of the only global, interagency, and multinational exercise programs, conducting over 30 operational air, maritime, and ground interdiction exercises involving over 70 nations. These exercises are hosted throughout the world by individual PSI participants and help improve participants’ coordination mechanisms to support interdiction-related decision-making.

Third, and of the most immediate importance, the PSI provides a basis for cooperation among partners on specific actions when the need arises. Interdictions are information-driven and may involve one or several participating states, as geography and circumstances require. The PSI, however, is not a formal treaty-based organization, so it does not obligate participating states to take specific actions at certain times. By working together, PSI partners combine their capabilities to deter and stop proliferation wherever and whenever it takes place.

Question:How Can States Participate in the PSI?

A: States can become involved in the PSI in multiple ways.

  • Endorsing the PSI and the Statement of Interdiction Principles and indicating willingness to take all steps available to support PSI efforts.
  • Undertaking a review and providing information on current national legal authorities to undertake interdictions at sea, in the air, or on land, and indicating willingness to strengthen authorities, where appropriate.
  • Identifying specific national "assets" that might contribute to PSI efforts (e.g., military and law enforcement capabilities, technical experts, legal advisors, etc.).
  • Providing points of contact for PSI assistance requests and other operational activities, and establishing appropriate internal government processes to coordinate PSI response efforts.
  • Being willing to actively participate in PSI interdiction training exercises and actual operations as opportunities arise.
  • Being willing to conclude relevant agreements (e.g., boarding arrangements) or otherwise to establish a concrete basis for cooperation with PSI efforts.

Cooperation by flag, coastal, or transshipment states, and states along major air shipment corridors is particularly essential to counterproliferation efforts involving cargoes in transit

PSI Operational Considerations

Question: What is an interdiction?

PSI partners define interdiction broadly as any action, based on sufficient information and consistent with national authorities and international legal frameworks, that results in the denial, delay or disruption of a shipment of proliferation concern. Shipments of concern may be transported by air, sea, or land. PSI participants seek to interdict shipments of proliferation concern at the moment of maximum legal authority and will employ any appropriate lever of national power, e.g., diplomatic (demarche), operational or military (hail and query to verify shipment, shipboarding), law enforcement / customs (port inspections), etc to achieve the objective.

One example of an interdiction is when a PSI partner sends a diplomatic demarche that alerts another partner to a suspect shipment that is scheduled to stop in that partner’s port. This sharing of information creates an opportunity for the partner to inspect – and seize, if necessary – the suspect shipment. An interdiction may also occur when a PSI participant recalls goods shipped by a domestic company that are in violation of that country’s export control laws. Perhaps the most recognized image of an interdiction is a naval boarding on the high seas. While these may occur, they are rare.

Question: What is the status of cargoes following seizure? How will determination on final disposition of seized cargoes be made?

A: Disposition depends on the precise circumstances of the particular case and is typically resolved in accordance with the laws of the state that conducted the seizure.

Question: Which state leads and/or coordinates a PSI action?

A: Each interdiction case will evolve differently. In general, a PSI participating state will provide information and seek help from others in acting to investigate and, if warranted, stop a shipment. This state may request action by other PSI participants. Those states that choose to be involved will coordinate among themselves on action needed.

Question: The PSI works to stop proliferation by air, land and sea. How are air shipments of proliferation concern interdicted?

A: Though the media emphasize maritime interdictions, PSI actions may be taken to interdict shipments transported by land and air. PSI exercises have been held to practice interdictions in all three environments. PSI experts have exchanged information on their respective legal authorities regarding potential air interceptions, and are continuing to discuss how these authorities might be applied.

Question: Are there mechanisms to verify reliability of intelligence used for interdictions?

A: The United States only pursues interdiction efforts where we believe there is a solid case for doing so. The judgment regarding the reliability of information used for interdictions is a national decision that must be made by each PSI participant government.

Question: How is information transmitted among PSI participants?

A: Each state that seeks to participate in the PSI is asked to identify an appropriate point of contact for sharing information, in the event a specific interdiction effort requires its active efforts or support.

However, sensitive information on specific interdiction cases will ordinarily be shared only with those states involved in the actual interdiction effort. There is no intent to make such intelligence available to all PSI states.

Question: How are proliferators “punished” when caught?

A: It depends on the precise circumstances of particular cases. A proliferation facilitator who has broken the law is subject to prosecution, usually in that entity’s home state.

Question: Will the PSI affect legitimate dual-use commerce?

A: Cooperation to stop the proliferation trade will facilitate legitimate trade by decreasing the risk that it will be exploited by the deceptive, and often illegal, practices of proliferators. As time goes on, private industries may prefer to do business with PSI participants, as they demonstrate their commitment to protecting international commerce from those who hide proliferation within legitimate trade routes and practices.

PSI participants will not stop and inspect every shipment that might involve items that could be used in proliferation program. The intent is to take action based on solid information regarding shipments that are believed to be destined for states or non-state actors of proliferation concern. Legitimate dual-use commerce will very rarely be affected by PSI activities.

PSI in the Broader Nonproliferation Context

Question: How does the PSI fit with the Container Security Initiative (CSI)?

A: The PSI and the CSI are complementary, in that both are operational efforts in support of national security objectives to enhance global maritime security by improving our ability to prevent shipments of illicit cargo. The Container Security Initiative is focused on maritime cargoes bound for (or from) the United States; PSI addresses cargoes in transit, wherever they may be -- at sea, in the air, and on land worldwide. CSI is creating adequate capabilities at major ports to screen cargo containers to ensure they do not contain problematic items. PSI efforts include action against shipments throughout the transportation continuum, not just when they arrive in a port.

Question: What is the relationship between PSI and formal nonproliferation structures such as the Missile Technology Control Regime (MTCR), Organization for the Prohibition of Chemical Weapons (OPCW), and the Nuclear Non-Proliferation Treaty (NPT)?

A: The United States, like many other countries, has a broad nonproliferation strategy, of which PSI is a key component. Given the complex nature of the nonproliferation problem, it is essential that countries leverage all tools available to them, including nonproliferation treaties, multilateral export control regimes, national export controls, enforcement measures, and interdiction, to stop the dangerous trade in WMD and related items. The PSI complements these existing tools to help prevent the proliferation of WMD, their delivery systems, and related materials. It does not replace other nonproliferation mechanisms, but provides an operational mechanism when proliferators evade these regimes. In this way, PSI plays a unique role in this broad strategy and offers policy makers additional options for addressing the proliferation threat.

Question: What is the relationship between PSI and international organizations such as the UN?

A: While PSI activities may be informed by efforts in other fora, the PSI Statement of Interdiction Principles does not establish any mechanism for formal cooperation with the UN or any other multilateral or international bodies. PSI participants have found, however, that participation in the PSI is an effective way to implement their obligations under United Nations Security Council Resolutions 1540, 1673, 1695, 1718, 1737, 1747, and 1803.

There is broad international support for the PSI, including at the UN. It is noteworthy that the United Nations’ High-Level Panel on Threats, Challenges and Change recommended in its December 2004 Report to the Secretary General that "all States should be encouraged to join this voluntary initiative."

The PSI SOP states that activities will be undertaken consistent with national legal authorities and relevant international law and frameworks. If an activity is authorized under a UNSC resolution, then it could be cited by a PSI participant as authority for its participation in an interdiction.

Question: What is the relationship between the PSI SOP and UN Security Council Resolution 1540?

A: UNSCR 1540 and the PSI SOP are mutually reinforcing and are legally and politically compatible. PSI participants have found that participation in the PSI is an effective way to implement their obligations under United Nations Security Council Resolutions 1540.

UN Security Council Resolution 1540 recognizes the threat to international peace and security posed by the proliferation of weapons of mass destruction (WMD) and outlines concrete actions states can take to counter this threat.

Operative paragraph 10 of UNSCR 1540 calls upon all states – in accordance with their national legal authorities and legislation and consistent with international law – to take cooperative action to prevent the illicit trafficking in nuclear, chemical or biological weapons, their means of delivery and related materials. This obligation can be met, if necessary, through interdiction, and the PSI helps countries improve their capabilities to organize for and conduct interdictions.

Furthermore, UNSCR 1540’s decision under Chapter VII of the UN Charter that all states shall develop effective laws as well as border, national export, transshipment, end-user and physical protection controls to prevent proliferation is consistent with and, in fact, bolsters the SOP’s calls for nations to "review and work to strengthen their relevant national legal authorities where necessary … (and) international law and frameworks in appropriate ways to support these commitments."

Question: Given that PSI operates within the framework of UNSCR 1718, 1737, 1747, 1803, and 1540, does the Initiative target specific states for interdiction efforts?

A: The PSI is a voluntary initiative aimed at the global proliferation threat posed by all state and non-state actors of proliferation concern. Through UNSCRs 1718, 1737, 1747 and 1803 the international community sent unambiguous messages: North Korea must eliminate its nuclear weapons and nuclear programs and stop development and proliferation of WMD and missiles; Iran must fulfill its international obligations and stop its enrichment, reprocessing and heavy water-related activities. The PSI is one effective way for states to implement the sanctions contained in UNSCRs 1718, 1737, 1747, and 1803.

Question: Can a party to the NPT (nuclear or non-nuclear weapons state) join in seizing nuclear materials without violating its NPT commitments?

A: Yes, NPT parties can participate in an effort to seize WMD-related shipments. As part of a PSI action, partners may be called upon to provide technical, security, or legal assistance, depending on the circumstances. In such cases, states would, of course, need to abide by their obligations under the NPT with respect to disposing or safeguarding of materials.

Question: How does PSI relate to other interdiction efforts, such as counternarcotics?

A: To the extent that efforts in other areas – such as the prevention of trafficking in narcotics – have developed procedures that may be useful models for PSI efforts, PSI partners may draw on them to support capacity-building efforts. For example, PSI partners have been able to improve the way they conduct interdictions of WMD-related items by extracting lessons learned from similar activities undertaken in as part of their counternarcotics efforts.

PSI Activities

Question: What is the Operational Expert Group (OEG)?

A. The PSI Operational Experts Group (OEG), a group of military, law enforcement, intelligence, legal, and diplomatic experts from twenty PSI participates states, meets regularly to develop operational concepts, organize the PSI exercise program, share information about national legal authorities, and pursue cooperation with key industry sectors. The OEG works on behalf of all PSI partners and strives to share its insights and experiences through bilateral and multilateral outreach efforts.

Question: When and how are operational activities planned for the future?

A: PSI operational activities – including training exercises and relevant workshops – evolve through discussions among PSI partners. In general, training events are proposed at periodic Operational Experts Group meetings and incorporated into a two-year exercise schedule that maximizes sustained participation. The current PSI exercise schedule in available through the U.S. Department of State website at http://www.state.gov/t/isn/c10390.htm.

Question: How are PSI efforts funded? Are provisions being made to provide technical assistance to states that currently lack capabilities to contribute fully to PSI efforts?

A: Each participant state is responsible for funding its own efforts in support of the PSI. That said, the U.S. wants to make sure that countries have the capacity to take effective action, and would examine, at a PSI participating state’s request, the possibility of offering capacity building assistance to certain states to help them develop more effective operational capabilities in support of the PSI.

Q: Who organizes or hosts PSI functions?

A: The PSI is not a formal organization with a budget and headquarters, but rather an interdiction partnership among participating states taking steps consistent with their respective national legal authorities and international law and frameworks to deter, disrupt and prevent WMD proliferation. Experts from twenty leading PSI endorsing states meet three to four times annually in the Operational Experts Group (OEG) to consider ways to enhance WMD interdiction capabilities of all PSI participants and build support for the PSI. The Office of Secretary of Defense leads the U.S. delegation to the OEG meetings.

Q: Are there different types of exercises or a different focus for a given exercise?

A: PSI exercises range in size and complexity. Some exercises do not involve any military assets but instead engage diplomatic channels, practice interagency coordination, and examine the use of law enforcement or customs authorities to stop WMD proliferation. Others are PSI “table-top exercises,” which explore scenarios and determine solutions for ground, port, and/or air interdictions through moderated discussions among experts. The most common PSI exercises combine table-tops and actual interdiction operations at sea with military assets from multiple nations practicing the tracking and boarding of a ship. U.S. participation ranges from observing an exercise to providing numerous ships, aircraft, and military and interagency personnel to a multinational exercise force.

Q: How many countries typically participate in a PSI exercise?

A:. Exercise participation ranges from two countries to more than a dozen. For instance, the PSI maritime and port interdiction exercise Guistir co-hosted by France and Djibouti and conducted in March 2008 involved 12 nations in the table-top and interdiction phases of the exercise.

Q: What is a typical scenario for a PSI interdiction exercise?

A: The scenario depends on the objectives of the exercise. In the case of a “table-top” exercise, the objective might focus on sharing information to stop or track the movement of money through notional financial organizations. An air, ground, or port interdiction exercise involving law enforcement and customs officials might have an objective to improve the effectiveness of procedures to seize cargo at an airport, international border, or large port, and its disposition following seizure. A large-scale maritime interdiction exercise requiring a ship-boarding will normally involve multiple objectives designed to test international, interagency, multinational military and internal military coordination. Exercise organizers will create notional countries, non-state actors, front companies, and financial institutions that seek to engage in WMD trafficking. The culminating point of such a complex scenario would require tracking the movement and seizing an item that succeeds in becoming cargo on a commercial ship destined for a notional country of proliferation concern.

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