This thesis explains Pakistan‘s post 9/11 foreign policy trends during the President Musharraf administration. Drawing upon analytical review of a diverse range of available literature on the subject, the thesis interprets various factors‘ contribution to Pakistani policy objectives and actions adopted during 2001-2008. It addresses a gap in the relevant literature and moves beyond the available different causal explanations often contested by different intellectual complications and political rhetoric.By drawing upon the concept of the security dilemma in the post 9/11 international politics as a lens to understand the nature of Pakistan‘s regional and domestic specific security and strategic compulsions, this research investigates and explains the dynamics which drove Gen. Musharraf‘s pursuit of specific policy action in spite of being nuclear power, its U-Turn on support for the Taliban. In doing this, it highlights the extent to which changed post 9/11 Pakistan''s foreign policy reinforced the immediate catalysts for Pakistan''s global and regional relations in the aftermath of the incident of 9/11. The primary argument of the thesis is that Musharraf''s post 9/11 foreign policy trends contributed to the hardening of Pakistan''s strategic, economic, socio-ethno-political perspectives, creating more complexities for Pakistan to pursue its regional and national policy interests; which were mainly at variance with the US global objectives in the post 9/11 scenario. Secondly, it argues that Pakistan-US relations during this period were driven by a ‗Security Dilemma (Complex)'' mindset, causing a shift between US global and Pakistan''s regional and domestic policy trends and objectives entailing different transformations. Post Musharraf civilian leadership is still struggling to imbibe post 9/11 Pakistan''s foreign policy divergent trends to protect Pakistan''s policy objectives.