India's main opposition party, widely expected to win the national election, is considering revising the country's "no first use" doctrine on nuclear weapons.
The potential change, analysts said, would evoke strong reaction from Pakistan and scrutiny from China.
In a possible sign of a more aggressive foreign policy under Hindu nationalist Narendra Modi should his Bharatiya Janata Party (BJP) form the next government, the party said in its campaign manifesto released on Monday that it would revise the country's nuclear doctrine to make it more "relevant to challenges of current times".
The BJP, which combined with coalition partners is poised to win more seats than the ruling Congress Party according to surveys, did not elaborate on how it would revise and update the nuclear doctrine. But Indian media outlets and analysts have interpreted this as a possible reversal of the "no first use" policy, adopted after the country's first nuclear tests in 1998. India's current policy prohibits it from initiating a nuclear strike and says it must only respond with punitive measures should deterrence fail.
Mohan Guruswamy, a former government official involved in drafting and negotiating the country's nuclear policy between 1998 and 1999, said India had been under pressure from Western nations, Japan and China to adopt the "no first use" policy.
But in the face of India's changing perceptions of its security environment, Guruswamy said the time had come for a change.
"Pakistan has a big arsenal, and China has been supplying nuclear technology and missiles to Pakistan," and continued to do so, said Guruswamy, who is now chairman of the New Delhi-based Centre for Policy Alternatives think tank.
Pakistan does not have a "no first use" policy. China's biannual defence white paper, released released a year ago, omitted for the first time a promise never to use its own nuclear weapons first.
Analysts said the suggestion of a change to the nuclear doctrine was aimed mainly at India's arch-rival Pakistan but would inevitably cause unease in China.
"It is likely that Pakistan may strongly react to the proposed revision … China will wait and watch," said Rup Narayan Das, a senior fellow with Institute for Defence Studies and Analyses.
Sun Shihai, a South Asia expert at the Chinese Academy of Social Sciences, said such a revision could backfire on India.
"Pakistan would respond with much stronger nuclear policy, and China would be very unhappy," he said.