Nuclear-weapons components are sometimes moved by helicopter and sometimes moved over roads. And instead of moving nuclear material in armored, well-defended convoys, the SPD prefers to move material by subterfuge, in civilian-style vehicles without noticeable defenses, in the regular flow of traffic. According to both Pakistani and American sources, vans with a modest security profile are sometimes the preferred conveyance. And according to a senior U.S. intelligence official, the Pakistanis have begun using this low-security method to transfer not merely the “de-mated” component nuclear parts but “mated” nuclear weapons. Western nuclear experts have feared that Pakistan is building small, “tactical” nuclear weapons for quick deployment on the battlefield. In fact, not only is Pakistan building these devices, it is also now moving them over roads.

What this means, in essence, is this: In a country that is home to the harshest variants of Muslim fundamentalism, and to the headquarters of the organizations that espouse these extremist ideologies, including al-Qaeda, the Haqqani network, and Lashkar-e-Taiba (which conducted the devastating terror attacks on Mumbai three years ago that killed nearly 200 civilians), nuclear bombs capable of destroying entire cities are transported in delivery vans on congested and dangerous roads. And Pakistani and American sources say that since the raid on Abbottabad, the Pakistanis have provoked anxiety inside the Pentagon by increasing the pace of these movements. In other words, the Pakistani government is willing to make its nuclear weapons more vulnerable to theft by jihadists simply to hide them from the United States, the country that funds much of its military budget…

According to military and intelligence sources, any response to a Pakistani nuclear crisis would involve something along the following lines: If a single weapon or a small amount of nuclear material were to go missing, the response would be small and contained—Abbottabad redux, although with a higher potential for U.S. casualties. The United States Joint Special Operations Command (JSOC) maintains rotating deployments of specially trained units in the region, most of them Navy SEALs and Army explosive-ordnance-disposal specialists, who are trained to deal with nuclear weapons that have fallen into the wrong hands. Their area of operation includes the former Soviet states, where there is a large amount of loose fissile material, and, of course, Pakistan. JSOC “has units and aircraft and parachutes on alert in the region for nuclear issues, and regularly inserts units and equipment for prep,” says a military official who was involved in supporting these technicians. Seizing or remotely disabling a weapon of mass destruction is what’s known in military jargon as a “render-safe mission”—and render-safe missions have evidently been successfully pulled off by JSOC in the past…

Much more challenging than capturing and disabling a loose nuke or two, however, would be seizing control of—or at least disabling—the entire Pakistani nuclear arsenal in the event of a jihadist coup, civil war, or other catastrophic event. This “disablement campaign,” as one former senior Special Operations planner calls it, would be the most taxing, most dangerous of any special mission that JSOC could find itself tasked with—orders of magnitude more difficult and expansive than Abbottabad. The scale of such an operation would be too large for U.S. Special Operations components alone, so an across-the-board disablement campaign would be led by U.S. Central Command—the area command that is responsible for the Middle East and Central Asia, and runs operations in Afghanistan and Iraq—and U.S. Pacific Command.

JSOC would take the lead, however, accompanied by civilian experts, and has been training for such an operation for years. JSOC forces are trained to breach the inner perimeters of nuclear installations, and then to find, secure, evacuate—or, if that’s not possible, to “render safe”—any live weapons. At the Nevada National Security Site, northwest of Las Vegas, Delta Force and SEAL Team Six squadrons practice “Deep Underground Shelter” penetrations, using extremely sensitive radiological detection devices that can pick up trace amounts of nuclear material and help Special Operations locate the precise spot where the fissile material is stored. JSOC has also built mock Pashtun villages, complete with hidden mock nuclear-storage depots, at a training facility on the East Coast, so SEALs and Delta Force operatives can practice there.