Washington -- Today, 90 nations have joined the United States to prevent some of the world’s most dangerous weapons from falling into terrorist hands, says President Bush.

Marking the fifth anniversary of the Proliferation Security Initiative (PSI), Bush hailed the effort’s “solid record of success” in confronting the complex threat posed by chemical, biological and nuclear weapons as well as illicit delivery networks willing to deliver weapons of mass destruction (WMD) to terrorists and hostile regimes.

“As a result of the collaborative efforts and training it sponsors, PSI is an increasingly effective tool to carry out real-world WMD-related interdictions,” Bush said in a May 28 statement, “from shutting down front companies to disrupting financial networks, prosecuting proliferators and stopping shipments of sensitive materials from reaching their intended destination.”

Launched in 2003 by 11 nations in Krakow, Poland, PSI is a new kind of partnership, said U.S. National Security Advisor Stephen Hadley. It brings diplomatic, law enforcement and military tools together to monitor global shipping and use existing legal authorities to intercept and seize illicit WMD-related shipments.

“PSI addresses a specific part of the problem: how to prevent proliferators from transferring weapons of mass destruction, their delivery systems, and related materials using the avenues of global commerce,” Hadley said in an address to PSI partners meeting in Washington May 28.

From the recent revelation of a secret Syrian nuclear reactor and internationally controversial nuclear programs in Iran and North Korea, the global proliferation threat is further complicated by increasing activity among nonstate actors, said Hadley, as illustrated by the breakup of an illicit network run by Pakistani nuclear scientist-turned-proliferator A.Q. Khan, as well as al-Qaida’s active efforts to acquire WMD for future attacks.

“The United States will hold any state, terrorist group or other nonstate actor or individual fully accountable for supporting or enabling terrorist efforts to obtain or use weapons of mass destruction -- whether by facilitating, financing or providing expertise or safe haven for such efforts,” Hadley said.

Since 2003, Hadley said, PSI partners have stopped several shipments of sensitive materials destined for Iran, North Korea and Syria, and continue to improve their ability to stop WMD trafficking by land, sea and air through a series of more than 30 multinational exercises.

PSI’s successes give nations an additional tool to safeguard the international community, Hadley said, complementing and reinforcing efforts by the United Nation’s International Atomic Energy Agency, parallel initiatives such as the 70-nation Global Initiative to Combat Nuclear Terrorism founded by the United States and Russia in 2006, and international agreements restricting trade in weapons-related technologies.

“PSI is a group of nations committed to be cops, a group that defines criminals clearly and a group committed to hold themselves and each other accountable for results,” Hadley said.

PSI is also a key component in a comprehensive plan against WMD proliferation, Hadley said, which includes further strengthening security at storage sites for dangerous materials; dismantling front companies and financial networks that could facilitate arms procurement; disrupting terrorist cells; and improving emergency response and recovery capabilities.

Looking to the future, Hadley called on PSI partners to improve information sharing, continue strengthening individual capabilities and make a redoubled effort to track terrorists’ and proliferators’ activities in the international financial system, freezing assets and closing down banks that help illicit WMD transfers.

“Much more work is needed,” Hadley said. “We will not be able to declare victory in this effort for many years to come.”

Bush’s statement and Hadley’s remarks are available from America.gov.