Secret British official papers from 30 years ago shed new light on the bloody confrontation between India and Pakistan in 1971.
The papers show that the US administration believed that India was about to dismember Pakistan.
The papers include secret transcripts of a summit meeting between the US and British leaders in December that year.
US President Richard Nixon and UK Prime Minister Edward Heath met in Bermuda as India and Pakistan fought their third war since gaining independence.
The papers relating to that war which resulted in the creation of Bangladesh, were released on Wednesday at the Public Record Office in London.
Cabinet pressures
This was the war that saw the break up of Pakistan's two separate territories, the flight of hundreds of thousands of refugees into India and then the birth of the new state of Bangladesh.
Beyond South Asia, many people saw it as a freedom struggle in which India played a helpful role against an oppressive military hierarchy in West Pakistan, led by General Yahya Khan.
But the transcripts of talks between the Indian Prime Minister, Indira Gandhi, and Mr Heath, and of the Heath-Nixon summit in Bermuda, show it was more than that.
Mrs Gandhi, on a visit to Britain, told Mr Heath of the pressure in her cabinet for her to take Pakistani territory and not return it.
India, she said, had seen Pakistan tying itself to China and now the United States also was establishing links with China.
Nixon's friendly overtures to the Chinese, and their closeness to Pakistan, she said, had made it necessary for India to sign a treaty with the Soviet Union.
Grim suspicions
Meanwhile, Yahya Khan was also seeking British support.
He wrote to Mr Heath outlining the Indian military build-up near Pakistani territory, which included seven army divisions confronting West Pakistan and eight near East Pakistan.
He also wrote about the deployment by India of comparable air force and naval threats.
The offensive posture adopted by India pointed in the direction of conflict, he wrote, not of peace.
The other papers, from the Bermuda summit, reinforce that position and highlight US fears.
They show that President Nixon and his foreign affairs adviser, Henry Kissinger, suspected India of scheming not just the separation of East Pakistan, but the break-up of West Pakistan and even moves against the Pakistani side of Kashmir.
Threatening posture
Nixon told the British that Mrs Gandhi was being steered by the Soviets, in response to the building of ties between Pakistan and China.
And Mr Kissinger said Nixon had secretly contacted the Soviet leadership to seek an assurance it would restrain India from breaking up West Pakistan.
But it was only after the American Seventh Fleet took up a threatening posture offshore that the promise was forthcoming.
The outcome, as the world knows, was the creation of Bangladesh, ruled by Sheikh Mujibur Rahman, and the temporary eclipse of military government in West Pakistan.
Mr Rahman was the civilian politician who had been jailed by General Yahya Khan.