From the most general of viewpoints, fundamentalism means a way of looking at the world from a strict and judgmental point of view. Consider the idea that fundamentalism holds its own views superior and tends to see modernity as inferior in contrast:
Fundamentalism is the demand for a strict adherence to specific theological doctrines usually understood as a reaction against Modernist theology, combined with a vigorous attack on outside threats to their religious culture.
For Hamid, his use of fundamentalism lies in how Changez rejects the United States and embraces a pro- Pakistan point of view towards the end of the narrative. Hamid constructs his fundamentalism in Changez in the same manner as the definition. Changez reveals himself to be someone that favors a strict interpretation of Islam, in contrast to the life he led in America. Changez possesses a strict reactionary impulse against what he perceives America to be doing in the region and in its foreign policy. He also perceives his fundamentalism to be a response to affirm the sovereignty of Pakistan, something that he sees as under siege or threat from the United States. In this, fundamentalism is defined in Changez's characterization.