Pakistani military leaders, the country’s de facto rulers, would have likely preferred a peaceful end to the conflict in Afghanistan, provided that their Taliban proxies held decisive influence in any future Afghan government. They would especially like to see the Taliban gain hold of the Afghan security apparatus, including the country’s leading national intelligence service, the National Directorate of Security. The generals in Rawalpindi believe the directorate is hostile to their country and that it works closely with their archenemy India to destabilize Pakistan by, for instance, supporting Pashtun and Baloch nationalists in Pakistan who are demanding political rights and regional autonomy.

Moreover, senior Pakistani military officers—and, not coincidently, the Taliban—consider Afghan President Ashraf Ghani (and his government) ineffective and illegitimate at best, and an American stooge at worst. Hence, the U.S. exit from Afghanistan has a silver lining for them: it removes the U.S. security umbrella that they believe New Delhi was using to expand its influence in Afghanistan at Islamabad’s expense.

https://carnegieendowment.org/2021/08/13/what-will-happen-to-afghanistan-and-pakistan-s-uneasy-border-pub-85152