Pakistan needs to take a look at the Dhofar Rebellion of Oman. Situation here is a bit similar to that one. a multi-pronged approach is needed:
- Increase in capacity+capability of FC: includes better training, better arms, drone and QRF backup
- Strengthening of intelligence network, use drones and intel network for a proactive approach, instead of reacting to an attack
- Deployment of SSG with FC
- Peace initiative: this includes a lot of work e.g. general pardon for all those who lay down arms; will include rehabilitation and employment opportunities. building educational infra (must have highly pro-pakistani teachers, also includes replacing existing teachers in local/regional unis, school, colleges with pro-pakistan instructors), health infra (similar pro-paksitan presence), road linkages etc. setting up of small household industries.
- Stricter regulation of Iran and Afghan border: this doesnt mean stopping the "smuggling" (people depend on that to survive as there are no other opportunities), rather regulating it, levying taxes etc. and letting the people go with their money.
- And all of this must be done in the backdrop of a heavy media campaign, that its the state that is providing security and safety, its the state that is providing health and education, its the state that is providing job opportunities etc.
this is the only way. they arent outsiders. they are funded and trained by outsiders, sure. but they themselves arent. keep using blind force, and they and their children and their children will keep on hating pakistan and anything associated with it. show them what incentives await them if they are a part of mainstream system, and they will slowly but surely start rejoining you.