To a casual observer, the behavior of the Pakistani state must seem puzzling, if not utterly inexplicable. Consider its relationship with the United States. Both U.S. and Pakistani officialdom have long insisted that Pakistan is a close ally that agreed to assist the United States in the global war on terror in the immediate aftermath of 9/11. It has helped bring a significant number of senior al-Qaeda leaders to justice, including 9/11 mastermind Khalid Sheikh Mohammed. It has permitted U.S. Predator aircraft to attack al-Qaeda and Taliban targets on Pakistani territory, despite strong opposition from the Pakistani public. It has also permitted U.S. armed forces to ship supplies to Afghanistan over critical land routes running through Pakistani territory.

Yet Pakistan is also supporting Afghan Taliban forces fighting against the United States in Afghanistan, providing them with safe haven on Pakistani territory and, it is widely believed, providing material support and military advice. Furthermore, it is doing so despite the fact that it is engaged in a nasty war with a Pakistani version of same that at one point controlled most of the country’s tribal areas and parts of Khyber Pakhtunkhwa province. Although the Pakistani Taliban are now on the run, they have not been destroyed. Indeed, with help from al-Qaeda and Pakistani jihadi groups based in Punjab they have sustained a damaging terrorism campaign in the urban heartland of the country. And while Pakistani authorities find themselves under attack by the jihadists they once nurtured, they persist in supporting another Pakistan-based jihadi organization, the Lashkar-e-Taiba, the group that carried out the Mumbai massacre of November 2008.

Pakistan’s relations with the United States have also come under severe strain. The Pakistanis arrested a CIA contractor named Raymond Davis on murder charges in late January and held him for almost two months, despite U.S. insistence that he had diplomatic immunity and should be released. Then in early May the world learned that Osama bin Laden had been hiding out in an army town less than a mile from the Pakistani version of West Point, suggesting that the Pakistanis were protecting him, are incompetent, or had not been trying very hard to find him.

The Feudals and the Army

If all this seems confusing, that’s because it is. But it is not inexplicable. The beginning of wisdom is to deconstruct the convenient appellation “Pakistani authorities.” It is an old disciplinary convention to speak of states as though they are monolithic actors. But it is not always so. With respect to Pakistan, it is impossible to fully understand developments there, in particular the Pakistani decision to use radical Islamic groups for state ends, without understanding...