This article aims at reviewing the changes that have occurred in South Asia in the post Cold War era after 9/11. In the post 9/11 scenario, US/NATO forces are present in Afghanistan. Indo -US strategic cooperation is rising especially in nuclear field. Pakistan has emerged as front-line state in US global war on terror but has been denied civil nuclear technology by the USA. In view of all these developments the article examines the changing pattern of US interests in South Asia focusing on US strategic policies towards India and Pakistan with special reference to war on terror, nonproliferation of nuclear weapons and US role in crisis management in South Asia. Furthermore, article also examines Indo-US strategic partnership and its implications for Pakistan, in the shape of a disturbed balance of power between the two arch rivals