RENEE MONTAGNE, host:
Domestic terrorists in Pakistan are becoming more and more sophisticated in their attacks on military bases and facilities there, and that's got the U.S. worried because there's also growing evidence that Pakistan is engaged in a determined effort to expand its arsenal of nuclear weapons. Nuclear experts in the U.S. say Pakistan would like to see the number of nuclear weapons double from the current estimates of the stockpile of roughly 100, and that raises fears that terrorists could be targeting the ever-widening network of nuclear facilities.
NPR's Mike Shuster has more.
MIKE SHUSTER: The U.S. relationship with Pakistan is fraught with anxiety and danger, and there is no more perilous element than Pakistan's nuclear weapons. Just listen to how Admiral Michael Mullen - the outgoing chairman of the Joint Chiefs of Staff - testified about Pakistan's nuclear weapons complex in a recent appearance before a Senate panel.
Admiral MICHAEL MULLEN (Chairman, Joint Chiefs of Staff): It's the proliferation of that technology, and it's the opportunity and the potential that it could fall into the hands of terrorists, many of whom are alive and well and seek that in that region.
SHUSTER: Pakistan is believed to have developed nuclear weapons in the 1980s. It carried out its first underground nuclear tests in 1998, and in the years since then, it has built up a stockpile of weapons to perhaps 100 or more. Recently, though, it has become clear that Pakistan's leaders want a bigger arsenal.
George Perkovich is a nuclear weapons expert at the Carnegie Endowment for International Peace.
Mr. GEORGE PERKOVICH (Nuclear Weapons Expert, Carnegie Endowment for International Peace): They're clear about this: When you talk to Pakistani military leaders, they're not shy about it. It's not a secret.
SHUSTER: In order to build a larger nuclear stockpile, Pakistan needs more plutonium. So Pakistan's leaders have embarked on a plan to expand its production facilities, including three new reactors that produce plutonium, the core explosive material in Pakistan's nuclear weapons.
Current and past satellite images show these reactors in various stages of construction, says David Albright, director of the Institute for Science and International Security.
Mr. DAVID ALBRIGHT (Director, Institute for Science and International Security): It's a dramatic scale-up of their ability to make plutonium for nuclear weapons. And the last one started to emerge just several months ago.
SHUSTER: The security of Pakistan's nuclear weapons has caused plenty of anxiety in the United States after evidence first emerged of the Pakistani bomb. And there is no doubt Pakistan has made significant efforts to protect these weapons: from layers of security at bases, to screening scientists, engineers and workers who handle them and their components, to special military units tasked with protecting them.
But, says Shaun Gregory, an expert on Pakistan at the University of Bradford in Britain, as the nuclear infrastructure expands, it presents ever-greater challenges for security.
Mr. SHAUN GREGORY (University of Bradford): The more nuclear weapons you have, the more nuclear weapons storage sites you have to have, the more nuclear weapons in transit at various times you have to have, the more people involved in the safety, security, manufacture, deployment, preparedness for use you have to have.
SHUSTER: Gregory has closely examined several attacks carried out by domestic terrorists on key military installations, including an attack on a naval air station in Karachi in May, and an attack on the army's general headquarters in Rawalpindi two years ago.
Their tactics have become increasingly sophisticated. The attackers wore army uniforms, displayed forged ID cards, penetrated layers of security checkpoints, used diversionary tactics and seized hostages, notes Gregory.
Mr. GREGORY: They appeared to have some insider knowledge about the base and its operations. They even knew where surveillance cameras were.
SHUSTER: These were not attacks on nuclear sites, but Gregory calls them a virtual blueprint for a potentially successful attack on a nuclear weapons facility.
Not all experts on Pakistan agree with Gregory's bleak assessment. George Perkovich notes that over the past decade, Pakistan has worked hard to secure these weapons and the complex infrastructure that spawns them. Perkovich calls the army the most competent institution in Pakistan, but with this qualification...
Mr. PERKOVICH: Though they may be the most competent institution in the country, they're not competent. And we've seen it from their point of view in the raid on Osama bin Laden, the raid on their own headquarters. So there's real cause of concern.
SHUSTER: The relationship between Pakistan and the United States is soaked in ambiguity and mistrust, and it seems to have reached a new low after the successful U.S. raid that killed Osama bin Laden.
Mr. PERKOVICH: What they're worried about is the U.S. stealing their nuclear weapons. So what they all point to is the raid on Osama bin Laden. That's the demonstration of the threat that they worry about.
SHUSTER: The U.S. has tried to help Pakistan safeguard its growing nuclear arsenal with some success, says Feroz Khan, who worked for many years inside the nuclear directorate known as the Strategic Plans Division.
Mr. FEROZ KHAN (Naval Postgraduate School): The United States is the most advanced nuclear power with the best practices in the world, and the Pakistani system actually tries to emulate them and learn from them. They have been very - not been shy of doing that.
SHUSTER: But for years, Pakistan has been fearful that in a crisis, the U.S. might try to seize its nuclear bombs. The bin Laden raid has led some in Pakistan to advocate dispersing the nuclear weapons to evermore numerous secret sites. But greater dispersal can lead to greater insecurity, with more people knowing about hiding more bombs in more places.
It's a paradox, concedes Feroz Khan, now with the Naval Postgraduate School in Monterey, California.
Mr. KHAN: It is a paradox that they seek a lot of cooperation from the United States, as well as far as nuclear security is concerned. But then they have to draw a line at some point, because it tips over to a place where they cannot fully trust the U.S. in terms of the location, as well.
SHUSTER: All of this has deepened concern in the United States among Pakistan experts. A growing nuclear infrastructure, an expanding weapons stockpile and ever more dangerous domestic attacks is a lethal combination, says David Albright.
Mr. ALBRIGHT: Particularly the most recent attack is really chilling. And you have to worry that nuclear sites could be targeted, and the attackers could muster the resources to do it.
SHUSTER: Shawn Gregory is willing to go so far as to predict an attack on a nuclear weapons site in Pakistan soon.
Mr. GREGORY: I think we are looking at the possibility of a very serious breach of Pakistan's nuclear security before too long.
SHUSTER: Those concerns were only heightened recently when several high-ranking Pakistani Army officers were arrested on suspicion of ties to a local militant group that advocates the violent overthrow of Pakistan's government.
Also, late last month came news that a cell phone seized in the raid on bin Laden's compound contained the numbers of a local militant group with ties to Pakistan's Inter-Services Intelligence agency, both examples of military or intelligence officials with connections to militant groups that might want to penetrate Pakistan's growing nuclear weapons infrastructure.
Mike Shuster, NPR News.
MONTAGNE: There's more troubling news this morning about Pakistan's nuclear program. It comes from a story in the Washington Post. The father of Pakistan's nuclear program, A.Q. Khan, is saying that years ago, military officers in Pakistan were paid by North Korea to pass on sensitive nuclear technology.
To back up his claim, Khan released a letter purportedly given to him by a North Korean official in 1998. The letter suggests that the North Korean government paid more than three-and-a-half million dollars to two high-ranking Pakistani military officers. They both deny the allegations, but the story worries U.S. officials. If true, it would indicate Pakistan's military was involved in illicit nuclear proliferation.
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