"Congratulations Mr President. You saved West Pakistan”
The reality is that from the very dawn of the war, the US administration, for the most part, misjudged the war. For instance, on March 29, 1971, Kissinger confidently told Nixon in a similar conversation that Pakistan was able to extinguish the unrest in its East

On December 17, 1971, then US President Richard Nixon was assured by his advisor Henry Kissinger that he had saved 'West Pakistan', according to private call records released by the United States Department of State. The conversation took place a day after Bangladesh's victory on December 16.
"Congratulations Mr President. You saved West Pakistan," Kissinger reassured President Nixon over the telephone. The assurance came after Indian premier Indira Gandhi unilaterally announced a ceasefire on the Western front.
India's involvement at the last stage greatly bolstered Bangladesh's struggle for liberation. Last two weeks, before Pakistan's forfeiting on December 16, 1971, India was fighting both on East and West fronts against the West Pakistani armed forces.
When India got involved and Pakistan's defeat seemed only a matter of time, the Nixon-Kissinger duo was worried. However, when India Gandhi declared a unilateral ceasefire, there was a big sigh of relief.
"Kissinger was playing a dubious role," PTI reported Pinak Chakravarty, former High Commissioner to Bangladesh, as saying. The US administration's objective was to befriend China using the Pakistanis as middlemen during the conflict months. His comments should be read as both an attempt to take credit with the Pakistanis in the face of a hopeless situation and a bid to please a difficult boss."
As soon as the Pakistani junta clamped down on the Eastern front, Kissinger told Nixon on March 26, 1971: "Apparently Yahya has got control of East Pakistan… all the experts were saying that 30,000 people (Pakistan Army at that time in the East) cannot get control of 75 million (Bangladesh's population) ... as of this moment it seems to be quiet."
However, the reality is that from the very dawn of the war, the US administration, for the most part, misjudged the war. For instance, on March 29, 1971, Kissinger confidently told Nixon in a similar conversation that Pakistan was able to extinguish the unrest in its East.
At the same time, Nixon justified citing the prior examples of how small forces could subdue and rule large populations. "Look what the Spanish did when they came in and took the Incas. Look what the British did when they took India."
However, according to Tariq Karim, former High Commissioner of Bangladesh to India, cited by PTI, "The Americans misread the situation completely. They failed to understand people's wish to be free and the fast pace with which the course of history changed."
In the final week to Bangladesh's victory, while the West Pakistan force was collapsing by the combined assault of Mukti Bahini (Bangladesh's freedom fighters) and the Indian Army, the Nixon-Kissinger duo was trying to save West Pakistan. To reverse or stop the war's momentum, Richard Nixon and Henry Kissinger were constantly brainstorming ideas.
As soon as Bangladesh's (then East Pakistan) liberation was certain, the US was worried that India would attack West Pakistan. US officials were especially worried over the possibility that India would take control of Pakistan occupied Kashmir (PoK). Fearing the possibility, the US was readying itself.
Indeed, as per declassified CIA reports, there were some high-level meetings as the tensions rose between India and Pakistan. It was evident that the US administration was preparing a plan if India should decimate the Pakistan Army, or attack the mainland or try to take back PoK.
More that, despite Nixon's warning to cut off economic help if India wars in East Pakistan, the US administration was baffled on how to execute it, the records reveal.
Kissinger said in a meeting with defence and CIA officials: "Both the President and the Secretary of State have warned the Indians that we will 'cut off' economic aid in case of war. But do we know what that means? No one has looked at the consequences or examined the means of implementing a cut off."
Another concern raised by Kissinger was that India would invade West Pakistan after winning the eastern conflict. "The Indian plan is now clear. They are going to move their forces from East Pakistan to the west. They will then smash the Pakistan land forces and air forces, annex the part of Kashmir and then call it off," he warned the officials.
Kissinger feared that West Pakistan would break off. Pakistan would lose Balochistan and the Northwest Frontier as well as Kashmir.
While declaring India the aggressor, the United States also dispatched its nuclear-capable aircraft carrier, USS Enterprise, to the Bay of Bengal and allowed its military supplies to be transferred to Pakistan despite the seeming illegality of that action as well. In fact, both India and Pakistan were officially cut off from American military support.
At the height of the crisis, the United States' foreign policy was heavily affected by the personal feelings of Nixon for General Yahya, as well as by West Pakistan's active participation in the China initiative and Kissinger's penchant for power politics. In fact, Yahya Khan played a significant intermediary role in creating closer ties between China and the US.
Pakistan was very necessary for the US at that time. Through Pakistan, the US was building relationships with China. Pakistan was a channel through which secret negotiations with China were ongoing.
Against this backdrop, the US sought to defuse the conflict between India and Pakistan. However, as the fighting went on, the Nixon government 'tilted' towards Pakistan as justified by Kissinger.
At the height of the Cold War, if Pakistan broke and the normalisation of relations with China would not happen, the US would be in trouble. In that context, for a short period, the crisis had dangerous potential to harm US interests and the Nixon-Kissinger duo was willing to take drastic measures.