Pakistan and the United States have had a history of complex relations since the former's inception. After the 9/11 attacks, changes were observed in the foreign policy of the United States towards Pakistan, followed by a strategic shift in Pakistan’s approach towards its ally in Afghanistan. This study aims to analyze the implications of the post-9/11 Pak-U.S. alliance by examining the impacts of terrorism and U.S. drone strikes on Pakistan’s national security. The theoretical framework focuses on John Mearsheimer’s theory of offensive realism. The study employs qualitative research methodology and focuses on secondary data. This research argues that as a result of the post-9/11 Pak-U.S. alliance, the national security of Pakistan was compromised. This study opines that a pragmatic foreign policy combined with a comprehensive national security approach is of paramount importance to Pakistan in order to survive and progress.