"India has become a victim of nuclear blackmail," said C. Raja Mohan, strategic affairs editor at The Hindu newspaper.

So, unable to go back, India is copying the example of the United States and the former Soviet Union at the height of the Cold War, building its nuclear deterrent to the point of mutually assured destruction so that neither side would dare go nuclear.

Over the course of this month, it has announced a new nuclear command and control structure, appointed a Commander-in-Chief of the so-called "strategic forces" and begun a fresh series of tests of nuclear-capable missiles.

"These are building blocks. Unless all of them are in place, the nuclear deterrent can neither be credible nor effective," said retired lieutenant-general V. R. Raghavan.

India massed its 1.1 million strong military along the border for 10 months last year in a standoff prompted by an attack on its parliament on December 13, 2000 which it blamed on Pakistan-based Kashmiri separatists.

Pakistan responded by mobilising its own half a million armed forces and the two sides came to the brink of war in June.

But under intense international pressure, India ultimately pulled back its troops rather than run the risk of a conventional conflict which could go nuclear, and analysts now concede that New Delhi gained little from the standoff.

India, which is mostly Hindu but officially secular, continues to accuse Islamic Pakistan of training and arming militants to attack Indian targets in a "proxy war" meant to wrest control of Kashmir, India's only Muslim-majority state.

Pakistan denies the charges, saying it gives only moral support to the Kashmiri "freedom struggle".

But Pakistani President Pervez Musharraf appeared to suggest last month it was the nuclear threat which prevented a fourth war between the two since independence from Britain in 1947.

Musharraf said the threat of a "non-conventional war" helped avert a conflict. While his spokesman later said he was talking about a popular uprising, India believed he meant a nuclear war.

MUTUALLY ASSURED DESTRUCTION

While tensions have eased between the two countries since the troop pull-back was announced in October, the battle is now on to make nuclear weapons too destructive to use.

Making that point, Indian Defence Minister George Fernandes said last week that if Pakistan used nuclear weapons on India, "there will be no Pakistan left when we have responded".

New Delhi this month set up a new Nuclear Command Authority, formalising the existing arrangement which gives the civilian political leadership under Prime Minister Atal Behari Vajpayee final power to authorise the use of nuclear arms.

The government also approved an alternative command chain to cover "all eventualities" and said in a statement that "nuclear retaliation to a first strike will be massive and designed to inflict unacceptable damage".

It gave no details, but last week named Air Marshal T. M. Asthana, a former fighter pilot, to lead a new strategic forces command.

Pakistan already has its own Nuclear Command and Control Authority made up of military, political and scientific officials with Musharraf having the final say.

Both countries are meanwhile refining their capacity to deliver nuclear bombs through ongoing missile tests, despite international calls for a halt to the South Asian arms race.

Last Thursday, India test-fired its nuclear-capable Agni-1 missile to a range of about 800 kms (500 miles) - a distance seen as targetting Pakistan.