The military outcome was a historic victory for the Indian Army, which succeeded in capturing the capital of the erstwhile East Pakistan, Dhaka, and taking more than 90,000 Pakistan Army personnel prisoner in just 13 days.
The political consequences were even more portentous, a new nation - Bangladesh - was created.
And an embittered Pakistan embarked on the path of making nuclear weapons, a development which has permanently altered the geopolitics of the region.
Past and present
The events of the time still resonate today. This year some half a dozen Jamaat-e-Islami leaders, who collaborated with the Pakistan Army in acts of genocide then, have been convicted and sentenced to varying terms of imprisonment and even death.
This year has also seen the publication of two significant books on the subject - Gary J. Bass's The Blood Telegram: Nixon, Kissinger and a Forgotten Genocide and Srinath Raghavan's 1971: A Global History of the Creation of Bangladesh.
Bass's book brings out the various facets of US policy towards the event, principally the manner in which the administration willfully ignored evidence of the large-scale killings that took place in the erstwhile East Pakistan because of their bias against India and a desire to protect Pakistan which was acting as a channel for Henry Kissinger and Richard Nixon's opening to China.
Raghavan's study has shown how the key steps towards the creation of Bangladesh must be seen through the prism of global and regional politics.
In his view, India's decision to delay intervention from March 1971, when the crackdown began, to December 3, when the Pakistanis attacked, was a grievous strategic error that led to much loss of life and property and suffering.
Over time, many myths have come to be associated with the events. One reason for this is that the government of India still refuses to issue an official history of the war, though a draft readied for publication was put up on the Times of India website in 2001 by this writer.
This has been cited by many scholars, but the fact of the matter is that this is not formally the official history.
Nevertheless, this history does reveal that the war did not quite begin on December 3 with the Pakistani air attack, but had actually began much earlier when Indian forces were ordered to make a limited push into the erstwhile East Pakistan from mid-November onward.
India had no plans of liberating Bangladesh as such. Army Headquarters' Operational Instruction No 53 of August 1971 saw its tasks as defending Sikkim and NEFA (Arunachal) against the Chinese, contain the Naga and Mizo insurgenciesand "destroy the bulk of the Pakistani forces in Eastern Theatre and occupy the major portion of East Bengal…."
The capture of Dhaka, which would involve the total defeat of the Pakistan army was not envisaged till December 9 and was the product of the quickly evolving "facts on the ground" created by individual commanders like Lt Gen Sagat Singh and exploited by the eastern command chief of staff, Lt Gen JFR Jacob.
But if India had splendid success in the east, its performance in the western theatre was less than stellar.
Unlike the east, in this theatre, there was near-parity between Indian and Pakistani forces in terms of armour and artillery. It is true that the forces there were asked to maintain a defensive posture, but limited offensives were part of the plan and carried out.
But even they were poorly executed and yielded few results.
After the war, the two sides traded territory they captured in Jammu & Kashmir, and the ledger shows that we came off worse, losing the important salient of Chamb.
Perhaps the failure that India would rue took place in the north. Here, in the Partapur sector where Siachen is located today, an attack by the Ladakh Scouts succeeded in moving 22 kilometres along a mountainous terrain in Arctic conditions prevalent in winter.
This success/failure was linked to the failure to capture the key objective of Olthinthang north of Kargil.
Had Indian forces managed to push beyond Turtok and capture Thang, the subsequent Pakistani adventure in Kargil in 1999 or the threat to Siachen would have been infructuous.
There were larger failures, too, in the western front - notably the inability of our main offensive in Shakargarh to take wing.
Likewise the war in the Rajasthan sector had an element of a farce in the manner in which the Indian and Pakistani offensives came unstuck, especially that of the hapless Pakistanis at Longewala.
The work of historians never ends. New material and newer perspectives provide the impetus for a fresh approach to something that happened a long time ago.
But for ordinary folk, history plays itself out in the shape and dynamics of contemporary events as is happening in the relationship between Bangladesh and India today.
Few will disagree, that while in terms of wars and alarums, the 1971 war may have been a short historical event, its larger development - the creation of Bangladesh - is something that has had lasting consequences, for the better or the worse.