It's been almost 15 years since the United States launched its program to help secure the world's largest nuclear stockpile -- in Russia. But analysts warn that the efforts on improving the security have been going at a terribly slow pace. They say the issue of securing the Russian nuclear arsenals is starting to fade from the two countries' agenda…. leaving more than half of the Russian nuclear arsenal vulnerable to possible terrorist attacks.

Experts agree that one of the most serious security threats in the world today is a terrorist detonating a nuclear device in a large city.  Modern Russia possesses about 16,000 nuclear warheads and 600 tons of nuclear material and is believed to be the likeliest source of material for such a device.

And it takes only a small amount of that material to put together a so-called "dirty bomb." At least several dozen cases of suspected smuggling of nuclear and radiological materials were reported in Russia over the last several years -- despite all the international efforts to secure Russian nuclear arsenal.

Robert Berls

Robert Berls, Senior Advisor for Russia Programs at the Nuclear Threat Initiative says only a part of Russian nukes have been secured.  “Russia has the largest stockpile of weapons-usable material, enough to make from 40,000 to 80,000 nuclear bombs, to some of the estimates. So that’s a lot of material, and a lot of it has been secured, but only about 50 percent.

The United States spends about half a billion dollars a year in threat-reduction projects. Since the early 1990s, the U.S. and Russia have worked to destroy or deactivate the Russian nuclear arsenal -- missiles, strategic bombers, submarines.

But the Russian nuclear research reactors are also at risk -- many of them are poorly guarded and very unlikely to be able to defend themselves against possible terrorist attacks.

“It's a problem that's worldwide,” says Mr. Berls. “There are approximately 128 research reactors around the world -- these are relatively small reactors quite often located in universities or scientific institutes that have relatively small amount of highly-enriched uranium.  But this highly-enriched uranium could very easily be used for developing nuclear weapons just as it could from a major storage facility in Russia or someplace else. And the problem with these research reactors is that they are in most cases very poorly secured.”

In 2002, when some 40 armed men took over a Moscow Dubrovka theater with some 800 people inside, it was revealed that they were also planning to take over the capital's Kurchatov Research Institute, which has several research nuclear reactors.

But despite the remaining threat, the Russian military seems to be increasingly opposed to having Americans too involved in securing the Russian nuclear facilities, fearing that such inspections could give the United States valuable insights into the Russian weapons' technology.

In the past, the Russian officials have said no foreign access will ever be provided to at least two facilities: large Russian weapons factories which store a quarter of Russian highly-enriched uranium and plutonium.

Rose Goethemuller, at Carnegie Endowment for International Peace, says that in the last five years, Russia and the United States have fallen away from the rich nuclear reduction dialogue they used to have.

Rose Goethemuller

“We do continue to target our weapons at the Russians and the Russians target their weapons at us. So we have a Cold War deployment of nuclear forces even if we don't consider the threat to be there anymore and we don't think the Russians are our enemies in the way we did in the past. I think it's very important that, just by accident or carelessness, that because they are still in this hair-trigger kind of deployment against each other, that we don't end up with the nuclear disaster.

Observers say that if the current rate of effort on dismantling Russian nuclear arsenal continues, it would take up to 14 years to complete the job, but since no one knows exactly how large the Russian nuclear arsenal is, it might take even longer.