Russia becomes the 15th and by far the largest country to sign up to the deal since it was put forward last year by U.S. President George W. Bush. Analysts call it a positive step but caution that many aspects of the PSI, as it is known for short, still need to be worked out.
The goal of the PSI, as formulated by the U.S. president, is to create a network of countries around the world that share intelligence and cooperate in halting potential shipments of weapons of mass destruction -- before they fall into the wrong hands. To that end, the PSI would allow member states to interdict and search any suspect building, ship, or plane on land, at sea, or in the air.
As long as the interdictions and searches take place within a signatory country's domestic borders, there are few legal issues. The problem is what happens when a ship or airplane, traveling in international waters or airspace, is suspected of carrying weapons of mass destruction?
Jon Wolfstahl, deputy director of the nonproliferation program at the Carnegie Endowment for International Peace in Washington, told RFE/RL that that has yet to be addressed. "Right now, the Proliferation Security Initiative is only set up to allow individual states to stop equipment and shipments -- whether it be by boat or plane or car -- in their own territory," he said. "It is in fact a coordinating mechanism to make sure that states are implementing their own laws and that their laws are tough enough. Where the PSI runs into problems is when ships or planes go international. And while we have had some success at coordinating with some of the major countries that flag ships, like Panama and Liberia, to gain permission in advance to board their vessels in international waters, the PSI still has no legal authority to stop what would otherwise be a legal shipment on a properly-flagged ship going through international waters."
Many suggest that the PSI, in order to resolve such questions, needs some type of international legal underpinning that goes beyond the ad hoc coalition the Bush administration has sought to build. Also, the precise definition of what constitutes a weapon of mass destruction and its components also needs to be codified to avoid potential disputes.
The natural institution to turn to would be the United Nations. But the United States, for its own policy reasons, has resisted that path, as Wolfstahl explained: "There are a number of potential mechanisms. One is a Security Council resolution that would empower members through Chapter 7 -- which is the part of the UN Charter which authorizes military action -- to stop shipments that are known to possess weapons materials, whether that be plutonium or highly-enriched uranium. The problem is that you would probably not get international agreement to stop ships that carry ballistic missiles, since North Korea is not the only exporter of these missiles, but many countries, including the United States, ship long-range ballistic missiles to countries like England."
And it is not just Britain that might prove controversial. Otfried Nassauer, director of the Berlin Information Center for Transatlantic Security, raised the question of Pakistan -- a U.S. ally whose top former nuclear scientist, Abdul Qadeer Khan, recently admitted to selling proliferation technology to Iran, North Korea, and Libya. A definition of what is a weapon of mass destruction as well as who should be put on a watch list needs to be agreed, he argued, if Washington is to avoid accusations of double standards.
"In case the U.S. delivers F-16 aircraft to Pakistan, F-16 aircraft can be nuclear-capable and this could be a case in which other countries could say: ' Wait a minute. Is Pakistan a target in respect to proliferation? Possibly yes. Therefore, such a transfer should not take place.' And on the other hand, the same could happen to the question of other recipients. I think it's both the technology question as well as the legitimate target question that clearly need to be defined," Nassauer said.
After that, Nassauer added, the participation of key shipping and technology-producing nations needs to be assured if the PSI initiative is to have teeth. "Most of the world's ships are flying the flags of smaller third-world countries and many of these countries need to be engaged over such an initiative to make it an effective one, especially if you don't want to violate the law," he said. "Then, it is surely clear that big countries like China and India need to be approached. The same might be true for Brazil and for other important countries in respect to trade and technologies."
After one year in existence, the nonproliferation initiative has had a mixed record. The seizure last summer of a vessel carrying explosives and weapons by the Greek authorities as it sailed through that country's territorial waters was claimed as a success by PSI proponents, as was the stopping of a ship off the Libyan coast.
But the United States and Spain, after jointly seizing a North Korean vessel carrying missiles off the coast of Yemen, were forced to release the cargo after a formal protest by the Yemeni authorities who noted that the shipment was destined for the Yemeni armed forces and thus did not violate international law.
Analysts and diplomats say interdictions and searches have a role to play in the fight against nonproliferation. But an internationally respected mechanism needs to be found that will also take into account countries' legitimate self-defense and trading needs.
The problem for many outside the United States is that the Bush administration's unilateralist approach to foreign policy, and especially its war in Iraq -- which was initially justified by the need to destroy alleged weapons of mass destruction that have yet to be found -- has undercut efforts to gain consensus on the issue.