As you may have heard, the U.S. foray into Pakistan to seize Osama bin Laden is, writes Yochi Dreazen at the National Journal, “fueling one of the country’s most enduring — and potentially dangerous — conspiracy theories: that the U.S. has designs on Pakistan’s nuclear arsenal and is prepared to send highly trained commandos into the country to seize control of the weapons.” First, it’s not fair to describe it as a conspiracy theory when, in fact, much of the American public, if polled, would no doubt wholeheartedly support such a campaign. Besides, writes Dreazen:

. . . the ease with which elite U.S. forces jammed Pakistan’s advanced air defense systems and mounted a precision operation deep inside Pakistani territory is eroding the Pakistani military’s standing in the eyes of its own people and raising new questions there about whether the U.S. could one day mount a similar push to grab Pakistan’s nuclear weapons.

Dreazen explains that Secretary of Gates Gates tried to reassure Pakistan.

Gates told a crowd of stony-faced senior Pakistani military officers at the country’s National Defence University that the he wanted to tell them “definitively” that the U.S. had “no desire to control Pakistan’s nuclear weapons.”

The United States may not “desire” but it might feel the need to assume control of Pakistan’s nuclear weapons. But it’s considerably more difficult than most people are aware. The West doesn’t know all the locations of Iran’s (however peaceful thus far) nuclear program, thus rendering preemptive bombing inevitably incomplete. Neither does the West know the location of all of Pakistan’s nuclear weapons, thus making it impossible to take complete control of its program.

I cited other reasons that the United States might feel the need to take such a drastic action in an article I wrote for Asia Times Online in 2009 titled Keeping Pakistan’s nukes extremist-free.

The London Independent’s Johann Hari quotes Scott Sagan, a nuclear security expert: “If Pakistan fears they may be attacked [by India or presumably jihadis], they have an incentive to take [the weapons] out of the [more secure] bunkers and put them out in the countryside.” Where, of course, there’s that much greater a chance they’ll be apprehended by jihadis.

In fact, the [New York] Times’ [David] Sanger reports that a top George W. Bush administration official expressed his fears to him that “some groups could try to provoke a confrontation between Pakistan and India in the hope that the Pakistani military would transport tactical nuclear weapons closer to the front lines, where they would be more vulnerable to seizure. Indeed, when the deadly terror attacks occurred in Mumbai [other] officials told [Sanger] they feared that one of the attackers’ motives might have been to trigger exactly that series of events.

[Also, writes Shaun Gregory of the University of Bradford’s Pakistan Security Research Unit] to facilitate maximum anticipation of an attack on its nuclear weapon sites (as well as to foil a quick ground strike) by India, Pakistan has located them in its west. “The unanticipated consequence,” he explains, is that the nuclear weapons are “either within or close to the more volatile tribal regions of Pakistan to the west and northwest of Islamabad.”

Still, Pakistan has the capability to keep its weapons safe. Professor Gregory describes just some of the precautions it takes with its nuclear-weapons program.

Pakistan has also designated certain facilities as no-fly zones and is acquiring specialized vehicles to prevent hijacking of nuclear materials when they’re most vulnerable — while in transit.

Other preventive measures Pakistan has taken include signing the Container Security Initiative, which provides Karachi with radiation detectors. Also, as part of a new US program called the Second Line of Defense Megaports, detectors and imaging equipment were set up in a port in southern Pakistan.

Meanwhile, Pakistan has access to an International Atomic Energy Agency database for sharing information about missing radiological materials. Finally, Pakistani officials have stated that their warheads have been fitted with permissive action links (PALs), a locking device which prevents detonation without a code.

Again, that’s barring Islamic extremist infiltration of the Pakistan military and the ISI.