Commandos help stop weapons smugglers on high seas.

Special operators are playing an active, but low-key part in the proliferation security initiative, which the United States launched in 2003 to stop the spread of weapons of mass destruction.

Initially, the initiative included the United States and 10 other countries: Australia, France, Germany, Italy, Japan, the Netherlands, Poland, Portugal, Spain and the United Kingdom. At last count, however, more than 60 nations had announced their support, according to Susan F. Burk, principal deputy assistant secretary of state for nonproliferation.

Participants are cooperating to develop a broad range of legal, diplomatic, economic, military and other tools-including interdiction of commercial shipping in the air, on land and at sea--to stop the movement of mass-casualty weapons.

In 2004, three nations, Panama, Liberia and the Republic of the Marshall Islands, signed reciprocal agreements with the United States, establishing procedures to board and search ocean-going vessels suspected of carrying weapons shipments, lf a U.S.-flagged vessel or one from one of the other three countries is suspected of carrying proliferation-related cargo, any party to the agreement can request the other to confirm the nationality of the ship in question and, if needed, to authorize the boarding, search and possible detention of the vessel and its cargo.

Those agreements together with commitments from proliferation security initiative partners mean that more than 50 percent of the world's commercial shipping fleet is now subject to rapid boarding, search and seizure by the United States.

To practice such operations, the United States has mounted 12 exercises involving vessels of the U.S. Navy and Coast Guard, as well as ships from other initiative participants. U.S.

Navy SEAL (seal, air and land) teams and Coast Guard law-enforcement detachments, both of which specialize in maritime interdiction operations, are frequent participants, as are the special-operations forces of other nations.

In November, for example, the U.S. Navy and Coast Guard ships participated in a multinational exercise in Sagami Bay, south of Tokyo, with vessels from Japan, France and Australia.

During the exercise, members of Japanese coast guard anti-terrorism units fast-roped down from a helicopter onto one suspect ship. U.S. Coast Guardsmen, joined by French and Australian special-operations troops, climbed into rigid-hull inflatable boats and raced to a second ship to search for contraband weapons material.

Real-life maritime-interdiction operations already are beginning to make a difference in the battle to contain weapons of mass destruction, said John R. Bolton, undersecretary of state for arms control and international security. He cited two successful interdictions. In 2002, a Spanish navy vessel intercepted a ship loaded with Scud missiles headed from North Korea to Libya. Spanish marines boarded the ship and took it over. In 2003, a German-owned ship, with uranium centrifuges also bound for Libya, was stopped by German and Italian forces.

The latter operation "was a major factor in the decision of the Libyan government to give up entirely the pursuit of weapons of mass destruction," Bolton told reporters.