This study highlights the Impact of Pakistan-Afghan relations and the emergence of TTP on the internal security of Pakistan. The influence of TTP's emergence on Pakistan's internal security and its impact on the Pak-Afghan relationship. Additionally, it highlights the impact of the Cold War on Afghanistan's economic conditions and the rise in extremism. The impact of terrorism on Pakistan's internal security and overall regional influence on the Pak-Afghan relationship. This study also gave us insight into the impact of refugee migration on Pakistan's internal security and the rise in extremism in the region. The impact of U.S. withdrawal on Afghanistan TTP reemergence and internal security of Pakistan. The rise of violence in the border areas is also discussed in the study, which is a huge threat to the internal security of Pakistan and the Pak-Afghan relationship. The Afghan Taliban and the TTP's historical and ideological bond is the reason for the rise in extremist activities in the region. Reasons for mistrust and lack of economic dependence between the countries are also highlighted.