Story behind the war

The Indo-Pakistani conflict was sparked by the Bangladesh Liberation War, a conflict between the traditionally dominant West Pakistanis and the majority East Pakistanis. The political tensions between East Bengal and West Pakistan had its origin in the creation of Pakistan as a result of the partition of India by the United Kingdom in 1947; the popular language movement in 1950; mass riots in East Bengal in 1964; and the mass protests in 1969. These led to the resignation of President Ayub Khan, who invited army chief General Yahya Khan to take over the central government. The geographical distance between the eastern and western wings of Pakistan was vast; East Pakistan lay over 1,600 kilometers (1,000 mi) away, which greatly hampered any attempt to integrate the Bengali and the Pakistani cultures.

To overcome the Bengali domination and prevent formation of the central government in Islamabad, the controversial One Unit program established the two wings of East and West Pakistan. West Pakistanis' opposition to these efforts made it difficult to effectively govern both wings. In 1969, President Yahya Khan announced the first general elections and disestablished the status of West Pakistan as a single province in 1970, in order to restore it to its original heterogeneous status comprising four provinces, as defined at the time of establishment of Pakistan in 1947. In addition, there were religious and racial tensions between Bengalis and the multi-ethnic West Pakistanis, as Bengalis looked different from the dominant West Pakistanis.

The general elections, held in 1970, resulted in East Pakistan's Awami League gaining 167 out of 169 seats for the East Pakistan Legislative Assembly, and a near-absolute majority in the 313-seat National Assembly, while the vote in West Pakistan was mostly won by the socialist Pakistan Peoples Party.The Awami League leader Sheikh Mujibur Rahman stressed his political position by presenting his Six Points and endorsing the Bengalis' right to govern. The League's election success caused many West Pakistanis to fear that it would allow the Bengalis to draft the constitution based on the six-points and liberalism.

To resolve the crisis, the Admiral Ahsan Mission was formed to provide recommendations. Its findings were met with favourable reviews from the political leaders of West Pakistan, with the exception of Zulfikar Ali Bhutto, the chairman of the Pakistan Peoples Party.

However, the military top brass vetoed the mission's proposal. Zulfikar Ali Bhutto endorsed the veto, and subsequently refused to yield the premiership of Pakistan to Sheikh Mujibur Rahman. The Awami League called for general strikes in the country. President Yahya Khan postponed the inauguration of the National Assembly, causing a shattering disillusionment to the Awami League and their supporters throughout East Pakistan. In reaction, Sheikh Mujibur Rahman called for general strikes that eventually shutdown the government, and dissidents in the East began targeting the ethnic Bihari community, which had supported West Pakistan.

In early March 1971, approximately 300 Biharis were slaughtered in riots by Bengali mobs in Chittagong alone. The Government of Pakistan used the "Bihari massacre" to justify its deployment of the military in East Pakistan on 25 March, when it initiated its military crackdown. President Yahya Khan called on the military – which was overwhelmingly led by West Pakistanis – to suppress dissent in the East, after accepting the resignation of Lieutenant-General Yaqub Ali Khan, the chief of staff of the East-Pakistani military.

Mass arrests of dissidents began and, after several days of strikes and non-cooperation, the Pakistani military, led by Lieutenant-General Tikka Khan, cracked down on Dhaka on the night of 25 March 1971. The government outlawed the Awami League, which forced many of its members and sympathisers into refuge in Eastern India. Mujib was arrested on the night of 25/26 March 1971 at about 1:30 am (as per Radio Pakistan's news on 29 March 1971) and taken to West Pakistan. Operation Searchlight, followed by Operation Barisal, attempted to kill the intellectual elite of the east.

On 26 March 1971, Major Ziaur Rahman of Pakistan Army declared the independence of Bangladesh on behalf of Sheikh Mujibur Rahman.

In April, the exiled Awami League leaders formed a government-in-exile in Baidyanathtala of Meherpur. The East Pakistan Rifles and Bengali officers in Pakistan's army, navy, and marines, defected to the rebellion after taking refuge in different parts of India. The Bangladesh Force, namely the Mukti Bahini, consisting of Niyomito Bahini (Regular Force) and Oniyomito Bahini (Guerilla Force), was formed under the retired colonel Mohammad Ataul Gani Osmani.