Seymour Hersh, who won the Pulitzer prize for exposing the My Lai Massacre during the Vietnam War, writes in The New Yorker that the greatest fear about Pakistani nuclear weapons falling into the hands of terrorists comes not from the Taliban but from the likelihood of a mutiny in the Pakistani military by Islamic extremist officers.

The success of the latest attacks raised an obvious question: Are the bombs safe? Asked this question the day after the Rawalpindi raid, Secretary of State Hillary Clinton said, “We have confidence in the Pakistani government and the military’s control over nuclear weapons.” Clinton—whose own visit to Pakistan, two weeks later, would be disrupted by more terrorist bombs—added that, despite the attacks by the Taliban, “we see no evidence that they are going to take over the state.”

Clinton’s words sounded reassuring, and several current and former officials also said in interviews that the Pakistan Army was in full control of the nuclear arsenal. But the Taliban overrunning Islamabad is not the only, or even the greatest, concern. The principal fear is mutiny—that extremists inside the Pakistani military might stage a coup, take control of some nuclear assets, or even divert a warhead.

No conversation about such a mutiny is complete without a discussion of Hizb ut-Tahrir, and despite the dismissive approach of some of my fellow TI front-pagers, the US government is worried enough about the group that it has been discussed at top levels of the Obama administration.

A senior Obama Administration official brought up Hizb-ut-Tahrir, a Sunni organization whose goal is to establish the Caliphate. “They’ve penetrated the Pakistani military and now have cells in the Army,” he said. (The Pakistan Army denies this.) In one case, according to the official, Hizb ut-Tahrir had recruited members of a junior officer group, from the most élite Pakistani military academy, who had been sent to England for additional training.

“Where do these guys get socialized and exposed to Islamic evangelism and the fundamentalism narrative?” the Obama Administration official asked. “In services every Friday for Army officers, and at corps and unit meetings where they are addressed by senior commanders and clerics.”

For more about Hizb-ut-Tahrir, check the history of posts on the group here at Talk Islam.