No logical necessity for Pakistan to side with Occupation in Afghanistan [split]

As it is mentioned, it is 'reversal of roles'. Now Pakistan needs to secure its border from incoming militants and their financial/weapons/manpower support from Afghanistan, in order to secure the border we need to secure the areas adjoining the borders first i.e. FATA otherwise their onslaught on Pakistani areas (beyond FATA) will continue.

"Prevent use of FATA as havens" is now a secondary worry for Pakistan.