Not everything goes to the PM, a mere misconception.
The attack takes place, the retaliation occurs, a gunfight occurs, the local major or company commander phones the formation commander or his CO, and it is then relayed to the higher authorities, and then it goes to the COAS,(who gets a daily report), all while the fighting ensues.
Now, simply put, we are in no position to launch ten warheads in Bagram, and the US not either, but US is in a position to murder some Pakistanis, while we don't.
In nutshell, this is a result of ten years of ambiguity.
You constantly bring up the case of Parliament, this Parliament of just as useless as anything else in Pakistan. Kayani should stand trial, but not the PM and President?
IMO< you are mixing up two things here, retaliation, and attack.
You retaliate when the other guy attacks, and with the same force as the other guy.
You attack with large force in the aftermath of a previous attack.
Pakistan did retaliate at Salala, but we are in no position at all to attack BAgram.