The racial identity of Bengal played a significant role in shaping and determining the political discourse in South Asia at different periods of history. The most violent expression of this identity occurred during the 1970-71 crisis between East and West wings of Pakistan and culminated in the dismemberment of Pakistan and the emergence of separate independent state of Bangladesh with the support of India. This violent episode of assertion of racial identity was marked with drama, trauma and tragedy. The tragic memories of violence are still alive and affect the attitude of people and state as well. While for Bengalis the war of 1971 was a war of liberation and deliverance from tyrannical and exploitative rule of West Pakistan, for Indians the victory was a great national achievement and a good lesson and settling of score with Pakistan. For Pakistanis it was the act of betrayal from Bengalis and an Indian conspiracy. An attempt will be made in this study to understand the development of racial identity in East Bengal and its culmination in armed conflict of 1971. An effort will be made to understand the xenophobia of Bengali nationalists and the xenophobic response of Pakistani military. The study will trace historical and structural roots of this phenomenon to understand the way this xenophobia was politicized and to understand the dynamics of this crisis through application of xenophobic response of conflicting identities. Xenophobia, in East Pakistan, acquired the general character and was institutionalized and manifested itself in mass scale. This study will be an effort to approach this problem through historical perspective; where the humans’ social behavior determined and guided the political conduct of a certain community.