Afghanistan's incursion by the Soviet Union in 1979 enhanced the elements of extremism informer FATA. In the post-9/11 period, tribal areas of Pakistan became a hub of militants and terrorists.Meanwhile, the role of Pakistan in the War on Terror (WoT) increased elements of terrorism and instability in the country. Many terrorist organizations like Al-Qaeda, Haqqani Network and Tehreek-i-Taliban Pakistan and other small terrorist groups including the Islamic Movement of Uzbekistan (IMU) andLashkar-i-Jahangvi started terrorist activities in the shape of suicide attacks. The study attempts to explainvarious internal and external factors (Afghanistan) which contributed to enhancing extremism and terrorism in former FATA. Furthermore, the research explains the anti-state activities of above mentioned militant groups in the area.