The Indo-Pakistani war of 1971, also known as the third India-Pakistan 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).

The Indian Army is the land-based branch and largest component of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Army, and its professional head is the Chief of Army Staff (COAS). The Indian Army was established on 1 April 1895 alongside the long established presidency armies of the East India Company, which too were absorbed into it in 1903. Some princely states maintained their own armies which formed the Imperial Service Troops which, along with the Indian Army formed the land component of the Armed Forces of the Crown of India, responsible for the defence of the Indian Empire. The Imperial Service Troops were merged into the Indian Army after independence. The units and regiments of the Indian Army have diverse histories and have participated in several battles and campaigns around the world, earning many battle and theatre honours before and after Independence.