It is not a secret that CIA has a long woven presence in pakistan for decades to look after core strategical, geopolitical interests of USA in the region.
These so-called extremist can be termed as Illegitimate children born out of illict relationship of CIA and Pakistan army. They were concieved n delivered in early 80s to fight the evil communists and now nearly 3 decades later they have now become fully grown annacondas ready to eat anything and everything, be their own parents or the innocent helpless victims comming their way.
Read Charlie Wilson’s war See Rambo III