Operation Chengiz Khan in the context of "Indo-Pakistani war of 1971"

The Bangladesh Liberation War (Bengali: মুক্তিযুদ্ধ, pronounced [mukt̪iɟud̪d̪ʱo]), also known as the Bangladesh War of Independence, was an armed conflict sparked by the rise of the Bengali nationalist and self-determination movement in East Pakistan, which resulted in the independence of Bangladesh. The war began when the Pakistani military junta based in West Pakistan—under the orders of Yahya Khan—launched Operation Searchlight against East Pakistanis on the night of 25 March 1971, initiating the Bangladesh genocide.

In response to the violence, members of the Mukti Bahini—a guerrilla resistance movement formed by Bengali military, paramilitary and civilians—launched a mass guerrilla war against the Pakistani military, liberating numerous towns and cities in the war's initial months. At first, the Pakistan Army regained momentum during the monsoon, but Bengali guerrillas counterattacked by carrying out widespread sabotage, including through Operation Jackpot against the Pakistan Navy, while the nascent Bangladesh Air Force flew sorties against Pakistani military bases. India joined the war on 3 December 1971 in support of the Mukti Bahini, after Pakistan launched preemptive air strikes on northern India. The subsequent Indo-Pakistani War involved fighting on two fronts; with air supremacy achieved in the eastern theater and the rapid advance of the Allied Forces of Mukti Bahini and the Indian military, Pakistan surrendered in Dhaka on 16 December 1971, in what remains to date the largest surrender of armed personnel since the Second World War.

The Indo-Pakistani war of 1971, also known as the third Indo-Pakistani war, was a military confrontation between India and Pakistan that occurred during the Bangladesh Liberation War in East Pakistan from 3 December 1971 until the Pakistani capitulation in Dhaka on 16 December 1971. The war began with Pakistan's Operation Chengiz Khan, consisting of preemptive aerial strikes on eight Indian air stations. The strikes led to India declaring war on Pakistan, marking their entry into the war for East Pakistan's independence, on the side of Bengali nationalist forces. India's entry expanded the existing conflict with Indian and Pakistani forces engaging on both the eastern and western fronts.

Thirteen days after the war started, India achieved a clear upper hand, and the Eastern Command of the Pakistan military signed the instrument of surrender on 16 December 1971 in Dhaka, marking the formation of East Pakistan as the new nation of Bangladesh. Approximately 93,000 Pakistani servicemen were taken prisoner by the Indian Army, which included 79,676 to 81,000 uniformed personnel of the Pakistan Armed Forces, including some Bengali soldiers who had remained loyal to Pakistan. The remaining 10,324 to 12,500 prisoners were civilians, either family members of the military personnel or collaborators (Razakars).