What made India pull out troops and return the captured territory at the end of 1971 Indo-Pak war?

Question

Indian forces during 1971 had decimated the Pakistani troops in Eastern theater resulting in one of the largest post WWII surrender including 90,000 soldiers. While Pakistan was in a non-negotiable position, India still pulled out its troops liberating Bangladesh from Pakistan. But what actually made India pull out troops from Pakistan and give back the captured the territory?

Answer 1

The efforts of Pakistani military forces in Bangladesh to eliminate Bengali nationalist guerrilla movement, the Mukti Bahini, produced a major refugee crisis for the Government of India, with between eight and ten million Bengalis crossing the border into India to escape the violence of the Pakistani troops. The Prime Minister of India, Indira Gandhi, decided that the best means by which to solve the refugee crisis was to assist the Mukti Bahini to achieve the independence of Bangladesh. Once Bangladesh achieved its independence, the refugees could return home and, thus, leave India.

If the goal of Indira Gandhi's administration was to assist Bengali nationalists in winning independence for their nation, then a permanent occupation of Bangladesh by Indian forces or that annexation of Bangladesh by India would directly contradict Indira Gandhi's goal. Moreover, even if the Indian Government attempted to permanently occupy or annex Bangladesh, they would face the opposition of the Mukti Bahini guerrillas, resulting in, at best, an expensive war without any foreseeable end. In addition, if, instead of ending the fighting between Pakistani troops and the Mukti Bahini, the place of the Pakistani forces was taken by the Armed Forces of India - resulting in a continuation of fighting - the eight to ten million Bengali refugees in India would not likely be willing to return to their homes in Bangladesh.