The key objective of this project is to determine to what degree Pakistan has cooperated with the United States and what factors are responsible for the variance in Pakistan’s cooperation with the United States in the war against Al-Qaeda, the Afghan and Pakistani Taliban. To determine the responses of the Pakistani government especially of its army, which is the core decision making body on issues of national importance, this thesis disaggregates the Unite States’ demands against Al-Qaeda, the Afghan and Pakistan Taliban. The main purpose of identifying the demands against the three different terrorist organisations of various importance to the national security of the United States was to determine its effect on the Pakistani cooperation with the United States. This thesis provides an alternative explanation of the Pakistani cooperation with the United States against Al-Qaeda, the Afghan and Pakistani Taliban, which is different from the traditional one focused on the Indian factor. It argues that the Pakistani cooperation with the United States against Al-Qaeda, the Afghan and Pakistani Taliban is dependent on three variables; the perception of the Pakistani army of the United States’ commitment, the military capability of the Pakistani army and the domestic opposition in Pakistan to cooperation with the United States. These factors don’t only provide explanation to the variance in Pakistani cooperation against different groups but also across different times.