U.S. President Barack Obama fears that in the event that Pakistan disintegrates, it would spark a scramble for nuclear weapons, some of which could fall into the hands of Islamic militants.

According to a book by David E. Sanger, chief Washington correspondent of The New York Times, Pakistan is Obama’s “biggest single national security concern.” The president even told his senior aides that he had “the least power to prevent” the potential collapse of Pakistan.

Obama even received some intelligence suggesting that Tehrik-i-Taliban (TTP) -- an umbrella group of Islamic militants that operate in Pakistan’s northwestern tribal areas near Afghanistan -- might have obtained a nuclear weapon, or perhaps a “dirty bomb.”

The suspicions were never confirmed, although fears about Pakistan’s growing atomic arsenal are all too real.

The book, called “Confront and Conceal: Obama’s Secret War and Surprising Use of American Power,” also claims that nuclear officials from both countries periodically meet surreptitiously in locales like Abu Dhabi or London to discuss nuclear security and the detection and disablement of atomic weapons in Pakistan.

Pakistani officials reportedly told their U.S. counterparts that no weapons were missing from its nuclear arsenal.

However, during his appearance at a nuclear security summit in Seoul, South Korea, in March, Obama declared: “There are still too many bad actors in search of these dangerous materials and these dangerous materials are still vulnerable in too many places.”

As for TTP, the group has been blamed by Pakistani authorities for a number of terrorist acts, including the assassination of former Prime Minister Benazir Bhutto in 2007, as well as a multitude of attacks on Pakistani state officials and soldiers.

TTP leader Hakimullah Mahsud has vowed to dispatch suicide bombers to the U.S. and Europe to avenge the killing of Osama bin Laden. The attempted bombing of Times Square in New York City in May 2010 was linked to TTP.

The New York Times Barack obama Nuclear weapons South Korea