The security of any state remains important and a vital factor for the main key actors of international politics. The rise of terrorism after the American attack on Afghanistan in October 2001 has worsened the security situation of Pakistan to an unprecedented degree. US intervention in Afghanistan has brought a lot of foreign influence in this region but especially in Pakistan because of its special geo-strategic location in the region. Pakistan is facing serious challenges to its security. Ethnicity, sectarianism, and religious extremism are the fundamental variables of internal security threats to Pakistan. This paper argues about internal security threats to Pakistan. The interdependence of these various threats and their overall impact on internal security is the focus of this analysis. Pakistan needs to address and solve these national security threats and find a suitable solution in a reasonable timeframe to find its rightful place in the community of modern nations.