The beginning of the 21st Century witnessed the rise of religious militancy in a more severe form exemplified by the traumatic incident of 9/11. While the phenomenon has troubled a significant part of the world, Pakistan is no exception in this regard. This research explores the role of the Mahsud tribe in the rise of the religious militancy in South Waziristan Agency (SWA). It further investigates the impact of militancy on the socio-cultural and political transformation of the Mahsuds. The study undertakes this research based on theories of religious militancy, borderland dynamics, ungoverned spaces and transformation. The findings suggest that the rise of religious militancy in SWA among the Mahsud tribes can be viewed as transformation of tribal revenge into an ideological conflict, triggered by flawed state policies. These policies included, disregard of local culture and traditions in perpetrating military intervention, banning of different militant groups from SWA and FATA simultaneously, which gave them the raison d‘etre to unite against the state and intensify violence and the issues resulting from poor state governance and control. The study explores the unique tribal characteristics of the Mahsuds, such as asylum provision, autonomy and lack of centralized leadership, which had historically facilitated the rise of religious militancy during the colonial times, replicating itself in the post 9/11 period. The flawed state policies encouraged autonomy of the young tribesmen from local institutions of Jirga and Malikship, thereby facilitating them to join the militant movement in SWA. Moreover, such state policies, coupled with military operations caused confusion among the Mahsud tribes and forced them to neither support the military directly, nor halt the activities of the militants. The findings also contradict the widely held narrative that Mahsuds as a tribe participated in the fight against the state in SWA in post 2001 period. As the findings suggest, the religious elite, including the local Imams Madrassa dropouts and the Afghan war militants had a strong role in directly inciting violence and insurgency and influencing young tribesmen. The pre-mature military intervention further pushed the war affected tribesmen, especially the family members of injured/killed/disappeared, into militancy. However, due to several reasons, including the integration of the Mahsuds in the mainstream community of Pakistan, the larger majority of the tribesmen did not participate in the insurgency against the state. The research further explores the impacts of displacement on the socio-cultural and political institutions of the Mahsud tribe as a result of militancy and subsequent military operations. The migration/displacements severely impacted the tribesmen, including their socio-cultural and political institutions of Malikship and Jirga, thereby impacting their tribal identities. Other political implications include a progressive decline in levels of support to religious political parties by local tribesmen. There is a further impact evident through a general tendency to support non-violent ethnicity based social movements against state excesses. The study has primarily employed ethnographic based data collection tools for research, such as semi-structured interviews, informal discussions and personal observations to reach its findings.