Afraid to go in NW?
Dude how many times do we have to explain it to people like you?
Going into NW is an immense expense that Pakistan cannot afford right now. I'm sure after spending so much time on PDF you might've gleaned off the fact that NW is a harsh mountainous area, making the operation infinitely harder.
Even if we do, there's a 100% guarantee that the terrorists holed up there will run into Afghanistan, and ISAF/NATO will do nothing about it.
So yes, the PA is afraid. Afraid that their efforts will go to waste and Pakistan will sink deeper in the hole it's already in.