Editor’s note: this article is part of "Too Dangerous to Fail," an occasional series on nuclear security issues in Pakistan and beyond.

BOSTON — Pakistan, it appears, badly flubbed its role as America’s key partner in the global manhunt for Osama bin Laden.

The incident raises a critical question: can a government implicated in such profound incompetence or duplicitousness be trusted to safeguard the world from a nuclear catastrophe?

The stakes couldn’t be much higher. Pakistan is volatile cocktail of instability, extremism and nuclear warheads. While Western leaders routinely pay lip service to Islamabad’s efforts to safeguard its deadly weapons, the truth is that the U.S.-Pakistani alliance is marred by mistrust and ideological differences. As a result, the U.S. knows little about where the nukes are and whether they are well-protected.

As relations deteriorate, recent events add evidence to what U.S. officials have long alleged: that elements within the Pakistani government cooperate with international jihadi networks. Meanwhile, these networks appear increasingly sophisticated in their ability to infiltrate and attack the Pakistani military, the stewards of the world’s most vulnerable nuclear arsenal.

As such, the risk of terrorists grabbing Pakistani plutonium for a dirty bomb or nuclear explosion in a major city lurks as one of the world’s biggest threats, and the Obama administration lacks options to do much about it.

In recent years, Pakistan has launched a nuclear surge. Its arsenal — already twice the size of China’s, and more than adequate to level India’s cities — is the world’s fastest growing, poised to surpass France’s within the next decade. Last month, Newsweek published satellite photos that showed yet another new reactor under construction at its main weapons-plant. This fourth reactor will enable Pakistan to produce enough plutonium for 19 to 26 new bombs a year, according to the Institute for Science and International Security.

We also know that terrorists would like to get hold of bomb-grade material, either to use as a dirty bomb or to detonate in a Western capital. They only need about 11 pounds of plutonium to make a bomb as powerful as the one that decimated Hiroshima. That’s a small fraction of Pakistan’s annual production, and an amount that’s smaller than a grapefruit.

U.S. security officials remain concerned about the risk. Last week, CIA chief Leon Panetta told a Senate committee that the nukes worry him, “because of the danger [they] could end up in the wrong hands.” Underscoring the troubled relationship, on Friday, Panetta flew to Pakistan to confront generals with evidence of collusion between their officers and Taliban militants.

Likewise, Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, said in a 2008 speech, “To the best of my ability to understand it — and that is some ability — the weapons there are secure. ... [but] there are limits to what I know. Certainly at a worse-case scenario with respect to Pakistan, I worry a great deal about those weapons falling onto the hands of terrorists and either being proliferated or potentially used.”

On a reassuring note, it’s important to remember that Al Qaeda’s leadership has suffered numerous recent setbacks, with the killing of bin Laden, Fazul Abdullah Mohammed (architect of the 1998 U.S. embassy bombings) and Ilyas Kashmiri (implicated in the 2008 Mumbai attack). Moreover, much of what the group has done in recent years has shown signs of genuine ineptitude — take, for example, the 2009 Christmas day underwear bomber and the 2010 Times Square car bomber.

Indeed, some Western experts caution against panicking. “Nuclear terrorism is a serious threat, but reporting on this issue can be rather alarmist,” said Eric Auner, Policy Analyst for Nuclear Security at the American Security Project, a Washington think tank. “The Pakistani military … has a lot of incentives to protect the country’s nuclear assets. The weapons are the ultimate insurance policy against aggression from India. Pakistan would have much to lose if a terrorist group managed to use nuclear materials of Pakistani origin,” Auner wrote in an email to GlobalPost.

The insider threat

Pakistan vehemently denies the possibility of nukes escaping their hardened security measures. But analysts worry about two scenarios through which they could fall into the wrong hands: either quietly via a radicalized insider, or through an assault by a highly-sophisticated outsider.

The insider threat is considered more likely. An estimated 8,000 to 12,000 people work on Pakistan’s nuclear program, so there are plenty of opportunities for well-organized terrorists to get inside the door. Although only a smaller number have real access, it’s not hard to imagine that someone senior enough to do real damage could be persuaded to cooperate.

There is, in fact, precedent. Sultan Bashiruddin Mahmood, the former head of Pakistan’s plutonium program, became radicalized while working on the weapons program. In the latter years of his service, he shocked colleagues by telling them he wished to share Pakistan’s bomb with Muslims intent on making Islam the world’s dominant religious force, according to a NY Times report. He was forced to resign in 1999. Two years later, just as Al Qaeda was making final preparations for its attack on the U.S., he met with Osama bin Laden and his deputy Ayman al-Zawahiri, the Times reported. He was later arrested. (He was never prosecuted, probably to protect nuclear secrets; instead he’s been kept at home under tight surveillance, as has A.Q. Khan, father of Pakistan’s nuclear program, who shared technology with North Korea, Libya and Iran).

To counter the threat of a secretly-hostile insider, Pakistan has been exposed to the “personnel reliability programs” that the U.S. uses — essentially, screening operations to ensure the stability and trustworthiness of people working at nuclear facilities — according to Scott Sagan, a Stanford professor who co-directs the American Academy of Arts and Sciences' Global Nuclear Future Project. It’s difficult to know whether this has worked, however. “How effective [are] those programs in a radicalized country? We don’t know the details, so we need to hope that the Pakistanis are taking it very seriously,” Sagan said in a GlobalPost interview.

Read a GlobalPost interview with Scott Sagan.

In the past, when the country’s nuclear program was smaller, Sagan noted that Pakistan’s military had many more jihadi sympathizers, operating openly in its ranks. “They called them long-beards,” he said. Military brass encouraged religious devotion among officers in the 1970s and 80s, and in accordance with the conservative Muslim tradition, they didn’t shave. After 9/11, then-President Pervez Musharraf reportedly removed dozens of long-beards from the officer corps. These days, of course, it’s more difficult to recognize the radicals, and it’s impossible to know how many remain in the ranks.

Events in recent weeks have bolstered the evidence that there are powerful insiders in Pakistan’s government acting against the interests of the U.S.

In April, Chicago prosecutors quietly indicted a major in Pakistan’s spy agency for helping to plot the murders of six Americans as part of the November 2008 terror attacks that killed 166 people in Mumbai, India, many of them at the Taj Hotel — a bastion of wealthy foreign guests.

In mid-May, David Coleman Headley, a confessed Pakistani-American terrorist, delivered five days of testimony to a Chicago court describing “a close alliance between Pakistan's intelligence service and the Lashkar-i-Taiba terrorist group,” according to ProPublica. It was the Lashkar-i-Taiba that was deemed responsible for carrying out the 2008 Mumbai attacks.

While there’s no indication that terrorists have gotten close to Pakistan’s nukes, these cases show that the country is failing to keep its anti-Western radicals away from the levers of lethal power. As Sagan put it, “clearly some in the Pakistani [security forces] still maintain interest in and connections to jihadis, because they are utilizing some of them for [Pakistan’s] conflict with India. Whether that could become the Frankenstein monster that turns on the doctors who think they’re controlling it remains to be seen.”

A snatch and run operation

And what about the threat of nukes being seized through an attack by very capable outsiders, or by jihadis who are both sophisticated and who benefit from inside information?

Pakistani nuclear expert Brig. (retired) Shaukat Qadir told the BBC that highly trained troops would find it almost impossible to storm the country’s nuke facilities. The weapons are located hundreds of feet under ground, and their whereabouts are protected by intense secrecy, Qadir said. According to a U.S. Congressional Research Service report, the sites are protected by a force of 10,000 troops, commanded by a two-star general. Since 9/11, some of them have reportedly received military training in the U.S.

But consider the events of May 22, when six militants attacked the PNS Mehran naval air station in Karachi, Pakistan’s largest city.

Details of the attack suggest that the assailants benefited from extensive inside information. It was a well-executed military operation, in which 16 soldiers were killed and two U.S.-supplied surveillance planes were destroyed by a mere six militants. They scaled the base’s walls using ropes and ladders, and appeared well-informed about their targets and the base’s defenses. The assault, which took security forces 16 hours to quell, embarrassed the military and raised questions about its competence.

The attack also exposed allegations of ties between the military and Al Qaeda. On May 27, Pakistani journalist Syed Saleem Shahzad published an account in the Asia Times alleging that the naval base assailants were retaliating against “massive internal crackdowns on Al Qaeda affiliates within the navy.” Shahzad’s investigation, which quoted anonymous military officers, disclosed that the attack came “after talks failed between the navy and Al Qaeda over the release of naval officials arrested on suspicion of Al Qaeda links” (emphasis added).

Shahzad’s allegations were not well-received. On May 31, the 41-year-old father of three was found dead 100 miles from his car. His body showed signs of severe beating. Journalists and a representative of Human Rights Watch told the NY Times the murder bore the marks of Pakistani intelligence agencies. So rather than celebrating the arrest of alleged militant jihadis in the Navy, powerful forces in the country were apparently reluctant for the world to know how deeply Al Qaeda had infiltrated the military, or that the navy was willing to negotiate a possible release of the extremists, as Shahzad had detailed.

Some experts view the assault as part of a worrying trend of increasingly brazen operations by militants. In October 2009, gunmen in military uniforms executed a similarly well-planned assault against the army’s general headquarters near the capital, resulting in a hostage crisis. Just like the Karachi attack, the assailants were well-organized and appeared to have inside information.

“Terrorists have now developed tactics —including intelligence-gathering, inside help, use of uniforms and military vehicles, and coordinated use of explosives and small arms — that have allowed them to penetrate high-security bases and to defend space within them for many hours,” noted Shaun Gregory, professor of international security at Bradford University, in the U.K., in an email to GlobalPost. “These add up to a virtual blueprint for an attack on nuclear assets.”

The U.S.: the problem or the solution?

Scott Sagan points out a greater potential grab-and-run risk: terrorists may not need to penetrate one of Pakistan’s hardened military bases to obtain plutonium. Instead, in the future, they may be able to snatch it in remote outposts. Sagan explains that there are several threats that might prompt Pakistan to transport its arsenal out of hardened military bases and into the rugged countryside.

Heightened tensions with India could prompt generals to move nuclear materials to the countryside, to ensure that Pakistan maintained its strike capability regardless of an Indian attack. Relations between the neighbors remain tense. According to the Congressional Research Service, risk of nuclear war between them “ran high” during the 1999 Kargil crisis, when the simmering fight over Kashmir boiled over into an overt war.

Deep distrust of the U.S. is another potential trigger for dispersing the arsenal. “Pakistan has a deep fear that the United States is interested in forcibly seizing the country’s nuclear weapons and ‘de-nuclearizing’ it,” says Auner, of the American Security Project. Washington denies any such intentions. Yet Seal Team 6’s handiwork on bin Laden — showing that the U.S. could operate deep inside Pakistan, and right in the military’s heartland — only served to boost such suspicions.

The mistrust poses a sticky quandary for Washington: helping to safeguard Pakistan’s arsenal requires the U.S. to learn more about it, but any efforts to gain information increases Pakistan’s feeling of vulnerability, rendering the arsenal more dangerous. As such, despite the potential for catastrophe, there’s little that the U.S. can do to directly ensure that bits of the arsenal don’t slip into the wrong hands.

American policy toward Pakistan’s arsenal remains deeply, but perhaps necessarily, paradoxical. Washington sends billions in aid to Pakistan each year. It has reportedly spent $100 million to train the military and equip it to safeguard its arsenal. It also sells the country F-16s that, with modifications, could be used to deliver nuclear warheads, according to the National Security Council. On the other hand, Pakistan refuses to provide Washington with access or details about its program. And the U.S. does whatever it can to impede its ally’s nuclear goals — for example, the FBI recently announced the indictment of a Pakistani living in Maryland for allegedly exporting equipment needed for the program’s reactors.

Yet this “frenemy” relationship is about the best that can be expected. Safeguarding Pakistan’s nuclear arsenal is a complex challenge. Experts differ over the balance of carrots and sticks that should be used to get Pakistan to act in American interests. But most agree that the U.S. has more leverage with Pakistan as a partner, even as a begrudging partner, than as an adversary; that Washington is better off with a toe inside Islamabad’s nuclear tent than as a complete outsider. After all, the West has had much less success in using threats and sanctions to influence Iran and North Korea’s (far more modest) nuclear programs.

Read an interview with nuclear security expert Scott D. Sagan.

Follow David Case on Twitter: @DavidCaseReport