The Proliferation Security Initiative


Who we are

The Proliferation Security Initiative (PSI) is a multinational response to the challenge posed by the threat of the proliferation of weapons of mass destruction (WMD). It strives to co-ordinate participating states’ efforts, consistent with national legal authorities and relevant international law (e. g. UNSCR 1540) and frameworks, to stop proliferation related trade in WMDs, related materials and delivery systems. Hence, the PSI is a complement to existing counter proliferation efforts.

The PSI seeks to unite every state, regardless of size or location, concerned about the spread of WMD and willing to undertake the commitments in the Statement of Interdiction Principles. Endorsers of the PSI also seek to cooperate with any state whose ships, flags, ports, territorial waters, airspace, or land might be used for proliferation purposes by states and non-state actors of proliferation concern.

Launched in 2003, over one hundred states have endorsed the PSI Statement of Interdiction Principles to date. It is a voluntary initiative geared toward enhancing individual and collective partner nations’ capabilities to take timely and appropriate action to deal with a fast-changing proliferation threat environment. The PSI provides a platform for networking among states and coordination of their activities to counter proliferation. This flexible construct is well-suited to combat the proliferation activities the world is facing today.

PSI Endorsement

States become PSI participants by endorsing the PSI Statement of Interdiction Principles. By doing so, participants commit themselves to establish a coordinated and effective basis through which to impede and stop the trafficking in WMDs, their delivery systems, and related material.

With this important goal in mind, PSI is open to every state that wishes to contribute to a safer world.

PSI Statement of Interdiction Principles

The Operational Experts Group (OEG)

Within the PSI framework, 21 states form the Operational Experts Group (OEG). The OEG plays an essential role in ensuring the effectiveness of the PSI by:

  • leveraging related counter proliferation efforts;
  • contributing customs, law enforcement, military and other security experts and assets to interdiction exercises;
  • hosting PSI meetings, workshops, and exercises with other PSI-endorsing states; and
  • working with specific partner states to improve their capacity to combat the proliferation of WMDs.

For more detailed information about the OEG and an overview of OEG states, please click here

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