MOSCOW — At Moscow's Sheremetyevo airport and other major Russian international gateways, departing passengers and baggage must go through radioactivity detectors.
It's one of the most visible signs of Russia's efforts to stem the flow of nuclear contraband to states trying to develop atomic weapons. But in this country of deep nuclear expertise, long borders and fitful law enforcement, such showcase controls have limited effect. Critics contend they serve to mask Russia's reluctance to stop transfers of nuclear expertise and ballistic missile components.
"They've stonewalled us," said Stephen Blank, a professor of national security studies at the U.S. Army War College in Carlisle, Pa.
The dispute has left the single biggest gap in the blossoming strategic partnership between Moscow and Washington. It's sure to be on the agenda of the May 23-26 summit between Presidents Bush and Vladimir Putin, as it has been at every previous presidential encounter over the last decade.
U.S. officials say they are pressing Moscow hard on the proliferation issue, but they won't discuss exactly what Washington is demanding, other than an end to transfers of sensitive technology to Iran.
The United States alleges that Tehran is going all-out to become the world's next nuclear power. With Russian help, the Americans maintain, that goal is now just years away.
Russian officials insist their nation has no interest in seeing Iran armed with nuclear weapons. But Iran is Russia's key economic and political neighbor in the Caspian Sea region, and is seen here as a force for stability and a counter to growing U.S. influence in nearby Central Asia. Moscow also appreciates Iran's refusal to help separatist Muslims in Chechnya.
"The Russian government, for political reasons, may be tolerating a certain amount of leakage," said Gary Samore, former President Clinton's special assistant for nonproliferation, now at the International Institute for Strategic Studies in London.
However, Vladimir Orlov, director of the PIR Center for Political Studies in Moscow, says the Russian government has told institutes to severely limit contacts with Iranian scientists and to train them only with explicit permission from the security services.
"A very clear message has been sent by Russian officials to facilities throughout Russia and to Russian universities and technical institutes that 'Iranians' is a bad word," Orlov said, citing unnamed Russian officials.
Iran denies it is seeking nuclear weapons technology. "There is nothing about production of nuclear weapons in the agreement signed between Russia and Iran on use of the atom for peaceful purposes, for generating electrical power," Gholam Reza Shafei, Iran's ambassador to Moscow, said at a news conference in February.
U.S. officials decline to give concrete evidence for their accusations, saying they need to protect their sources and methods of surveillance. A. Norman Schindler, a CIA nonproliferation specialist, told a Senate subcommittee in September 2000 only that Russian institutions had helped Iranian counterparts with projects with "direct application to the production of weapons-grade fissile material."
In a December 2001 story in The New Yorker magazine, investigative journalist Seymour Hersh reported that Israel had handed the United States evidence that during the previous year, at least two Russian firms had sent Iran aluminum and steel materials that could be used for the centrifuges needed for nuclear bombs.
The Russian government says it has limited its nuclear cooperation with Iran to peaceful projects like the long-delayed Bushehr nuclear power plant. In 1995, Russia contracted with Iran to supply a 1,000 megawatt reactor and finish construction.
Although the International Atomic Energy Agency approved, the United States and Israel objected vigorously to Russia's participation. It's not so much the plant that causes concern as the doors it opens in Russia, U.S. experts argue.
"All the contacts between the Iranian and Russian nuclear establishments, plus all the money that's flowing from Iran to Russia for the project, give the Iranians access and allows them to try to acquire from Russia more sensitive nuclear technology," Samore said.
Analysts from the PIR Center wrote this spring that nuclear specialists returning from Bushehr had affirmed that "Iran's major objective is to form indigenous skills to accelerate its nuclear weapons program."
Russia insists the project is legitimate. it says it also has safeguards, chiefly the requirement that spent nuclear fuel be returned to Russia, not kept and enriched.
"The people working on the station now are construction specialists. The designing is being done here, the specialists are in Russia. Training will be here," said Vladimir Kuchinov, deputy chief of the foreign economic department of the Russian Atomic Energy Ministry.
Sergei Yakimov, chief of the export control department of the Russian Economic and Trade Ministry, said there is a widespread Russian suspicion that under the banner of fighting proliferation, Western countries are protecting their economic interests.
U.S. officials say the Russian leadership has not sent a clear message to law enforcement agencies that sensitive technology transfers must stop. U.S. experts accuse Russia's main security agency, the Federal Security Service, or FSB, of at best turning a blind eye to proliferation.
The nuclear and missile material from military plants "isn't just something you put in your trunk and drive off," Blank said. "The FSB is in all these factories."
Beyond the recriminations, some small patches of common ground are emerging. The United States has quietly dropped its insistence that Russia pull out of the Bushehr plant, insisting instead that Russian-Iranian nuclear cooperation end there, a senior U.S. administration official confirmed.
Speaking on condition of anonymity, he said Bushehr is a highly visible project, but the real obstacle to closer cooperation is Russia's "overall pattern of behavior."