On 25 March 1971, after an election won by an East Pakistani political party (the
Awami League) was ignored by the ruling (West Pakistani) establishment, rising political discontent and
cultural nationalism in East Pakistan was met by brutal
[27]and suppressive force from the ruling elite of the West Pakistan establishment, in what came to be termed as
Operation Searchlight. The violent crackdown by the Pakistan Army
[29] led to Awami League leader
Sheikh Mujibur Rahman declaring East Pakistan's independence as the state of
Bangladesh on 26 March 1971.Most Bengalis supported this move although
Islamists and Biharis opposed this and sided with the Pakistan Army instead.
Pakistani President
Agha Muhammad Yahya Khan ordered the Pakistani military to restore the Pakistani government's authority, beginning the civil war. The war led to a substantial number of refugees (estimated at the time to be about 10 million)flooding into the
eastern provinces of India.Facing a mounting humanitarian and economic crisis, India started actively aiding and organising the Bangladeshi resistance army known as the
Mukti Bahini.
Reaction to the defeat and dismemberment of half the nation was a shocking loss to top military and civilians alike. Few had expected that they would lose the formal war in under a fortnight, and there was also unsettlement over what was perceived as a meek surrender of the army in East Pakistan.
Yahya Khan's dictatorship collapsed and gave way to Bhutto, who took the opportunity to rise to power.
General Niazi, who surrendered along with 93,000 troops, was viewed with suspicion and contempt upon his return to Pakistan. He was shunned and branded a
traitor. The war also exposed the shortcomings of Pakistan's declared strategic doctrine that the "defence of East Pakistan lay in West Pakistan“.