[14] India previously possessed chemical weapons, but voluntarily destroyed its entire stockpile in 2009 — one of the seven countries to meet the OPCW extended deadline.

To reiterate the latter point, in October 2002, then-President A. P. J. Abdul Kalam asserted that "India will not make biological weapons.

In June 1997, India declared its stock of chemical weapons (1,045 tonnes of sulphur mustard).

As early as 26 June 1946, Jawaharlal Nehru, soon to be India's first Prime Minister, announced: As long as the world is constituted as it is, every country will have to devise and use the latest devices for its protection.

I have no doubt India will develop her scientific researches and I hope Indian scientists will use the atomic force for constructive purposes.

[34] Prime Minister Lal Bahadur Shastri opposed developing nuclear weapons but fell under intense political pressure, including elements within the ruling Indian National Congress.

As a result, Shastri announced that India would pursue the capability of what it called "peaceful nuclear explosions" that could be weaponized in the future.

[27] The situation changed again in the late 1980s after the 1987 Brasstacks crisis and the beginning of the Pakistani nuclear weapons program.

In 1989, Prime Minister Rajiv Gandhi gave Defense Secretary Naresh Chandra approval to develop the bomb.

[27] India performed further nuclear tests in 1998 (code-named "Operation Shakti") under Prime Minister Atal Bihari Vajpayee.

In 1998, as a response to the continuing tests, the United States and Japan imposed sanctions on India, which have since been lifted.

In August 1999, the Indian government released a draft of the doctrine[38] which asserts that nuclear weapons are solely for deterrence and that India will pursue a policy of "retaliation only".

The Joint Services SNC is the custodian of all of India's nuclear weapons, missiles and defense assets.

The National Security Advisor Shivshankar Menon reiterated a policy of "no first use" against nuclear weapon states and "non-use against non-nuclear weapon states" in a speech on the occasion of Golden Jubilee celebrations of National Defence College in New Delhi on 21 October 2010, a doctrine Menon said reflected India's "strategic culture, with its emphasis on minimal deterrence.

[39][40] In April 2013 Shyam Saran, convener of the National Security Advisory Board, affirmed that regardless of the size of a nuclear attack against India, be it a miniaturised version or a "big" missile, India will retaliate massively to inflict unacceptable damage.

[41] In 2016, Defence Minister Manohar Parrikar questioned the no-first-use policy, asking why India should "bind" itself when it is a "responsible nuclear power".

[46] Nuclear-armed fighter-bombers were India's first and only nuclear-capable strike force until 2003 when the country's first land-based nuclear ballistic missiles were fielded.

However, the Prithvi missiles are less useful for delivering nuclear weapons because they have a shorter range and must be deployed very close to the India–Pakistan border.

[58][59] A CIA report claimed that Russia provided technological aid to the naval nuclear propulsion program.

[62] Sagarika has already been test-fired from an underwater pontoon, but now DRDO is planning a full-fledged test of the missile from a submarine and for this purpose may use the services of the Russian Navy.

However, the Arihant class ballistic missile submarines will be only capable of carrying a maximum of four Agni-III SL.

[70][71] Samar Mubarakmand, a Pakistani nuclear physicist, asserted that if Shakti-I had been a thermonuclear test, the device had failed to fire.

[72] However, Harold M. Agnew, former director of the Los Alamos National Laboratory, said that India's assertion of having detonated a staged thermonuclear bomb was very much believable.

[73] The yield of India's hydrogen bomb test remains highly debatable among the Indian science community and international scholars.

[78] U.S. seismologist Jack Evernden has argued that for correct estimation of yields, one should 'account properly for geological and seismological differences between test sites.

In early February 1997, Foreign Minister I. K. Gujral reiterated India's opposition to the treaty, saying that "India favors any step aimed at destroying nuclear weapons, but considers that the treaty in its current form is not comprehensive and bans only certain types of tests."