Ancestors (British Indian army) of the same Pakistani soldiers were shouting the same slogans even back in 1940s when they fought Germany and its allies throughout the Middle East and Africa.
it is funny that some jawans were in Cairo, and when the procession of Shah Farouk came along, they started shouting Nara Takbeer Allaho Akbar. Shah was quiet amused as he couldn't figure out the meaning of these shouts.
They were not propagating Islamism back then, and they are not doing so now.
they are sons of soil who are ready to defend it against the Indians or the TTP.
Nothing more nothing less.
But you won't know, or won't accept if you do know their history.
Sadly.