Pakistan has been the Afghan Taliban's key foreign sponsor for decades, with Islamabad harboring the militant group's leadership during the nearly 20-year U.S.-led war in neighboring Afghanistan.
But since the Taliban seized power in August 2021, its ties with Islamabad have deteriorated amid deadly border clashes. More recently, the militants have accused Islamabad of permitting its air space to be used by U.S. drones to strike targets in Afghanistan. In turn, Pakistan has accused the Taliban of harboring terrorists.
Experts say the longstanding alliance, which dates back to the emergence of the Taliban in southern Afghanistan in the mid-1990s, is coming under unprecedented strain as their interests diverge.
"The Taliban may have accepted Pakistani support for years but do not wish to be Pakistani proxies forever," said Husain Haqqani of the Washington-based Hudson Institute who previously served as Pakistan's ambassador to the United States.
Demonstrators take part in a protest against Pakistani air strikes in Afghanistan's Khost Province on April 16.
Last month, the Taliban accused Pakistan of allowing U.S. drones to use its airspace to conduct strikes inside Afghanistan. The August 28 claim came after an American drone strike in Kabul killed Al-Qaeda leader Ayman al-Zawahri in July. Islamabad has denied involvement in or advanced knowledge of the strike.
On September 14, Islamabad accused the Taliban government of harboring Masood Azhar, head of the Jaish-e Mohammad (JeI) extremist group and a UN-blacklisted terrorist. The Taliban strongly rejected Pakistan's claims.
In his speech to the UN General Assembly on September 23, Pakistani Prime Minister Shehbaz Sharif said Islamabad "shares the key concern of the international community regarding the threat posed by major terrorist groups operating from Afghanistan."
SEE ALSO: Residents of Tribal Areas Deplore Airstrikes’ Civilian TollSharif mentioned the Islamic State-Khorasan (IS-K), the Tehrik-e Taliban Pakistan (TTP), Al-Qaeda, the East Turkistan Islamic Movement, and the Islamic Movement of Uzbekistan as groups based in Afghanistan that "need to be dealt with comprehensively, with the support and cooperation of the interim Afghan authorities."
The speech provoked a sharp rebuke from the Taliban, with Deputy Foreign Minister Sher Mohammad Abbas Stanikzai on September 27 claiming Islamabad was "receiving millions of dollars" from Washington for allowing American drones to conduct flights over Afghanistan.
"How long can we tolerate this?" Stanikzai asked a gathering in Kabul. "If we rise against this [Pakistani interference], no one will be able to stop us."
Pakistani Foreign Minister Shah Mehmood Qureshi (center) receives members of a Taliban delegation at the Foreign Office in Islamabad in October 2019.
Experts say another source of tension is the Taliban's unwillingness to crack down on the TTP, a close ideological and organizational ally. From its bases inside Afghanistan, the extremist group has intensified its insurgency against Islamabad in recent years.
The Afghan Taliban has mediated peace talks between Islamabad and the TTP, also known as the Pakistani Taliban. But doubts have been cast over the peace process as Pakistan has conducted air strikes against TTP fighters inside Afghanistan. There have also been suspected TTP attacks in Pakistan.
"Pakistan keeps assuming that the Taliban are reliant on them economically and politically," said Obaidullah Baheer, a lecturer at the American University of Afghanistan. "The Taliban, on the other hand, are overreacting to Pakistani statements because, for a long time, they were accused of being allied to Islamabad."
Graeme Smith, a consultant for the International Crisis Group, says Pakistan and the Taliban have many incentives to cooperate despite their differences. He cites the rapidly growing trade volume between Pakistan and Afghanistan.
"The relationship will remain very fractious," he said. "It's worth monitoring the flare-ups of violence, but the incentives for cooperation are overwhelming."