Pakistan army will also not do operation against Afghan Taliban because Launching operation against Afghan Taliban is against Pakistan,s national interest. Afghan Taliban has never attacked Pakistan they have no fight with Pakistan they are only fighting and defeating Americans and Nato in Afghanistan.
the group against which Pakistan is fighting is a different group known as Tehreek Taliban Pakistan which has done massive killings of Muslims in Pakistan. this group was made after 2007 it is funded by Indian intelligence agency Raw through Afghanistan border and doing operation against this group is in Pakistan,s interest.