The bin Laden raid is just the latest unilateral encroachment on Pakistani territory. Reports of official pushback are flooding in. This is being seen as the latest incident in a long history of American heavy-handedness. Drone strikes, anyone?

The issue of unmanned aircraft strikes has long been sensitive in Pakistan. It’s partly nationalist anger over the slaughter of innocent Pakistanis instead of the intended terrorist targets. But the real explanation lies in the fact that Pakistan is a multi-ethnic state in which the populous Punjab rules over Pashtun, Baluch and Sindhi minorities. The northwest border areas where the strikes are concentrated consist of 27 million Pashtuns. They never wanted to be part of Pakistan in the first place and were seeking an independent “Pashtunistan,” linked to the 20 million Pashtuns in adjacent areas of Afghanistan, when the departing British Raj handed them over to the new state of Pakistan in 1947.

For Islamabad, the drone strikes are politically dangerous because they politicize and radicalize hitherto quiescent tribesmen, increasing the possibility of a “Pashtunistan” that would break up Pakistan. To understand Islamabad’s anxieties, it is necessary to bear in mind that the 41 million Pashtuns on both sides of the border have a long history of political unity.

Prior to the British Raj, the Pashtuns had been united since 1747 under the banner of an Afghan empire that stretched eastward into the Punjabi heartland up to the Indus River. It was traumatic for them when the British seized 40,000 square miles of ancestral Pashtun territory between the Indus and the Khyber Pass—encompassing half the Pashtun population—and then imposed the Durand Line, formalizing their conquest. When the British subsequently handed over this territory to the new, Punjab-dominated government of Pakistan in 1947, they bequeathed an explosive, irredentist issue that has poisoned relations between Pakistan and Afghanistan and that continues to pose a giant question mark over the future of Pakistan.

At various times, Zahir Shah’s monarchy, Mohammed Daud’s republic and the short-lived Communist regime in Kabul have challenged Pakistan’s right to rule over its Pashtun areas, alternatively espousing the goal of an autonomous Pashtun state to be created within Pakistan, and independent “Pashtunistan” to be carved out of Pakistan or a “Greater Afghanistan” that directly annexes the lost territories.

The Soviet occupation of 1979 and the U.S. offensive against al-Qaeda and the Taliban that began in 2001 have produced deep divisions in Pashtun society that make the future of the “Pashtunistan” movement uncertain. The traditional supremacy of the malik over the mullah in tribal society was weakened when the United States, together with Islamist groups in Saudi Arabia and the Persian Gulf, channeled weapons aid and funding for the anti-Soviet resistance struggle to favored Islamist clients in Afghanistan at the behest of the Pakistan Directorate of Inter-Services Intelligence (ISI). The ISI’s objective was to build up surrogates opposed to the Pashtunistan concept. When these surrogates proved unable to consolidate their power after the Soviet forces left, the ISI turned to the Taliban, which had a Pashtun base but was dominated by clerical leaders with a pan-Islamist ideology. Significantly, however, the Taliban government that ruled from 1996 to 2001 did not accept the Durand Line despite Pakistani pressure to do so.

Notwithstanding the divisions in Pashtun society produced by convulsions of the past three decades and the resulting growth in the power of the mullah at the expense of the malik, the Pashtuns continue to have a powerful sense of collective identity rooted in an ancient tribal structure that still defines their lives. As the preeminent British expert on the Pashtuns, Richard Tapper, Professor Emeritus at the London School of Oriental and African Studies, has observed, “in spite of the endemic conflict among different Pashtun groups, the notion of ethnic and cultural unity of all Pashtuns has long been familiar to them as a symbolic complex of great potential for political unity.”

Pentagon spokesmen have made it clear that the drone strikes will continue even if they have to operate out of bases in Afghanistan. But Islamabad can retaliate by making good on its threats to limit the number of CIA agents permitted in Pakistan.

There have been two hundred thirty-four drone strikes in Pakistan since 2004, which have killed between 1,439 and 2,290 suspected terrorists, according to a New America Foundation study. By stirring up Pashtun nationalism, the drones are doing incalculable damage to long-term U.S. interests in Pakistan and Afghanistan, and should be limited to those rare cases in which solid actionable intelligence identifies a key al-Qaeda or Taliban leader.