Washington: More than 18 years after India and the US signed a civil nuclear deal, its full potential and promise along with the larger bilateral partnership is yet to be realised, according to a top American expert.

While New Delhi is yet to remove obstacles that prevent its purchase of nuclear reactors from the United States, Washington has not been able to match the policy with vision, Ashley J Tellis, the Tata Chair for Strategic Affairs and a senior fellow at the prestigious Carnegie Endowment for International Peace, said.

US President Joe Biden's ambition to finally fructify the 2005 civil nuclear agreement cannot end with the sale of US nuclear reactors to India. Rather, it must extend to revising long-standing US policies that continue to make the existence of India's nuclear weapons programme an insuperable obstacle to deepened technological cooperation, he asserted in an opinion piece published by Carnegie Endowment for International Peace on Monday.

"Where India is concerned, New Delhi is long overdue in removing the obstacles that prevent its purchase of nuclear reactors from the United States, consistent with the written commitments it made during the implementation of the nuclear deal. Where the United States is concerned, a different challenge persists that is no less urgent: matching policy with vision," he added.

Tellis noted that after Biden's visit to India in September, the joint statement declared that the two leaders "welcomed intensified consultations between the relevant entities on both sides to expand opportunities for facilitating India-US collaboration in nuclear energy, including in development of next-generation small modular reactor technologies in a collaborative mode".

Realising this promise, however, will require solutions that have eluded the two sides thus far, said the Indian-American expert.

Westinghouse, the supplier of high-output nuclear power plants, remains skittish about sales to India with the absence of a durable assurance of limited liability in the event of an accident.

At least one other American company, Holtec International, which supplies small modular reactors (SMRs), already operates a components factory in India and is eager to explore SMR sales in the country and across West Asia but these discussions are still in the early stages.

Given the Biden administration's interest in consummating the civil nuclear agreement, as well as India's interest in expanding foreign participation in its nuclear energy programme, it is past time for the Modi government to rectify the nuclear liability problems that it has inherited ironically due to the obstructiveness of Modi's own party, albeit long before he led it, Tellis wrote.

The cleanest solution to the current predicament would be to amend India's Civil Liability for Nuclear Damage Act (CLNDA) to bring it in line with the Convention on Supplementary Compensation for Nuclear Damage (CSC) by channelling all liability in case of a nuclear accident solely to the operator of a nuclear plant, with the operator in turn protecting its interests by relying on an insurance pool for financial safety. India has already moved to create such an insurance pool pursuant to the CLNDA but it has not been fully funded yet, he wrote.

According to Tellis, even as India looks for ways to realise the commercial promise of the civil nuclear agreement -- an objective that the Biden administration must be congratulated for making its own -- the administration still has another bigger and more consequential task arising out of this accord: addressing the issue of India's nuclear weapons programme in the US grand strategy.

Tellis said the inherited nonproliferation rules and how they are implemented not only prevent India from enjoying the full benefits of the agreement but even more importantly, subvert the overarching objective that drove its negotiation -- assisting India's ascendancy to create the Asian multipolarity that balances China's rise.

"On this count, both the administration and the US Congress are of one mind. Consequently, it is now time for the executive branch to bring its application of the non-proliferation rules in accord with its core strategic goal of building Indian capabilities to effectively resist expanding Chinese power," he asserted.