Brajesh Mishra, who was National Security Advisor during the Pokharan nuclear tests in 1998, today questioned Prime Minister Manmohan Singh’s assurance to US President George Bush on segregation of Indian civilian and military nuclear facilities, saying it amounts to acceptance of a ‘‘cap’’ on the size of New Delhi’s minimum credible nuclear deterrent.

Speaking to The Indian Express in New Delhi, Mishra said: ‘‘The promise made yesterday in Washington means that we are accepting a cap on the size of our nuclear deterrent with a small number of nuclear weapons.’’

According to Mishra, the NDA government had offered to put a ‘‘couple of existing nuclear facilities under full scope guards but the offer was never accepted’’ by the US.

‘‘The idea was that there would be enough fissile material from the reactors not under safeguards for India’s minimum credible deterrent...But by effecting a separation between civilian and nuclear facilities, India would in fact be agreeing to the basic provision of a future fissile material cut-off treaty even before an international treaty on that crucial subject is negotiated and put into effect by other nuclear weapon states,’’ he said.

He said the UPA government’s argument that New Delhi would only be doing what other nuclear weapon states had already done did not hold water. ‘‘The size of their nuclear deterrent is immense in comparison to ours,’’ Mishra said.

Observers in Washington are surprised at these comments. Sources in the Indian delegation dismiss Mishra’s main argument that the deal with the US involves a “cap” or a limit on the size of India’s nuclear weapon programme.

Sources said hard-ball negotiations with the US were built on the “basic premise that a cap on the size of India’s arsenal will be absolutely unacceptable” to the UPA government.

Those familiar with the internal discussions inside the Bush Administration say US non-proliferation hardliners wanted a limit on the size of India’s nuclear weapons material as a precondition for civilian nuclear cooperation with India. At the political level, the American leadership recognised that such a precondition would be a non-starter and rejected it out of the negotiating framework.

Sources see little merit in Mishra’s argument that separating the civil and military programmes will limit the production of weapons-useable material for the Indian programme, essentially plutonium.

Under the pact it is India’s sovereign right to define which of its facilities are civilian and which are military. The joint statement makes it clear that it is India’s call to first “identify” which are the civilian facilities and then “separate” them from the military programme. The pact with the US obliges India only to “file” a notification with the International Atomic Energy Agency on what it considers are its civilian facilities.

Like other nuclear weapon states, India is under no obligation to spell out which of its facilities are “military”.

The language of the joint statement is plain enough to suggest that it is entirely up to India to choose which of its facilities it would put under “voluntary” international safeguards.

This in essence is no different from the offer of the BJP government, in its earlier negotiations with the US on the nuclear issue, to put some of India’s nuclear reactors under safeguards.

Sources said the BJP government had, in fact, seriously considered the separation of India’s civilian and military facilities in return from much fewer political gains from the United States.

The historic nuclear accord with the US, sources say, now allows comprehensive civil nuclear energy cooperation with “no limits what so ever” on India’s own ability to produce fissile material for nuclear weapons.

In an ideal world, the BJP and the principal functionaries of its rule during 1998-2004 should be taking credit for laying the foundation for India’s nuclear diplomacy. But in the real world, BJP might be deeply uncomfortable with the fact that the Congress and the UPA are reaping the rewards. This is not very different from what was seen in 1998—the NDA reaping gains from the Congress government's preparations for nuclear tests in December 1995.

That the UPA has been able to secure better terms than the BJP, ultimately, has to do with the fact that India, irrespective of which party governs it, has become stronger by the day over the last decade.