Why is Pakistan’s military repressing a huge, nonviolent Pashtun protest movement?

On January 27, a man named Manzoor Pashteen was arrested in the middle of the night in Peshawar. He faced five charges, including sedition, criminal conspiracy, attacking Pakistan’s sovereignty, and promoting ethnic hatred. Pashteen is the young leader of the Pashtun Tahafuz (Protection) Movement, or the PTM: a non-violent protest movement demanding rights for Pashtuns in Pakistan’s former Federally Administered Tribal Areas.