India was the seventh country to develop nuclear weapons. , India is estimated to possess 190 nuclear weapons. India previously developed chemical weapons, and is a party to the Biological Weapons Convention and the Chemical Weapons Convention. India is one of four states widely believed to possess nuclear weapons that are not a party to the Nuclear Non-Proliferation Treaty.

India operates a nuclear triad, consisting of approximately 80 Prithvi-II and Agni-series ballistic missiles from short to intercontinental range, 48 Mirage 2000H and Jaguar IS fighter-bombers, and 24 Sagarika submarine-launched ballistic missiles aboard two Arihant-class submarines. India is developing multiple independently targetable reentry vehicle-capable land and submarine-based ballistic missiles.

India maintains a no first use nuclear policy and credible minimum deterrence doctrine. Its no first use is qualified in that while India states it generally will not use nuclear weapons first, it may do so in the event of "a major attack against India, or Indian forces anywhere, by biological or chemical weapons."

In 1974, India conducted the Smiling Buddha nuclear test. In 1998, India carried out the Operation Shakti series of nuclear weapon tests. It is unclear if India has developed boosted fission or thermonuclear weapons. Initially, India's primary strategic concern was a conflict with China, while modern Indian policy focuses on potential conflict with Pakistan, which developed its own nuclear capability in 1983. India is not a party to the NPT and has not signed Comprehensive Nuclear-Test-Ban Treaty, considering both treaties flawed and discriminatory. India is the only non-NPT state to receive a waiver from the Nuclear Suppliers Group, allowing international nuclear industry commerce since 2008.

India previously declared 1,044 tons of sulfur mustard in 1997, and destroyed its stockpile by 2009, one of the seven countries to meet the OPCW extended deadline. India also participates in the Missile Technology Control Regime, Australia Group, and Hague Code of Conduct.

Biological weapons

India has ratified the Biological Weapons Convention (BWC) and pledges to abide by its obligations since 1974. There is no clear evidence, circumstantial or otherwise, that directly points toward an offensive biologicial weapons programme. India does possess the scientific capability and infrastructure to launch an offensive biological programme. In terms of delivery, India also possesses the capability to produce aerosols and has numerous potential delivery systems ranging from crop dusters to sophisticated ballistic missiles.

No information exists in the public domain suggesting interest by the India in the delivery of biological agents by these or any other means. To reiterate the latter point, in October 2002, then-Indian president Abdul Kalam asserted that "India will not make biological weapons. It is cruel to human beings".

Chemical weapons

In 1992, India signed the Chemical Weapons Convention (CWC), becoming one of the original signatories of the CWC in 1993, and ratified it on 2 September 1996.

In 1980, India established its chemical weapons programme, and officially notified Pakistan in 1992 of its intention of destroying its inventory of harmful chemical agents. In June 1997, India declared its stock of chemical weapons ( of sulphur mustard). By the end of 2006, India had destroyed more than 75 percent of its chemical weapons and material stockpile and was granted an extension for destroying the remaining stocks by April 2009 and was expected to achieve 100 percent destruction within that time frame.

India informed the OPCW and the United Nations in May 2009 that it had destroyed its stockpile of chemical weapons in compliance with the international Chemical Weapons Convention, making it the third country, after South Korea and Albania, to do so.Ritu Sharma (14 May 2009). India destroys its chemical weapons stockpile. IANS. Yahoo News. . Verification was completed by the chemical weapons inspectors of the United Nations. The policy change on the chemical weapons was largely influenced from the views of former Indian army chief General Sundarji that a country having the capability of making nuclear weapons does not need to have chemical weapons, since the dread of chemical weapons could be created only in countries that do not have nuclear weapons. Others suggested that the fact that India has found chemical weapons dispensable highlighted its confidence in the conventional weapons system at its command.

India has an advanced commercial chemical industry, and produces the bulk of its chemicals for domestic consumption. It is also widely acknowledged that India has an extensive civilian chemical and pharmaceutical industry and annually exports considerable quantities of chemicals to countries such as the United Kingdom, the United States, and Taiwan.

Nuclear weapons

As early as 26 June 1946, Jawaharlal Nehru, soon to be India's first Prime Minister, announced:

Nehru pursued a policy of formally foregoing nuclear weapons while at the same time constructing a civilian nuclear programme and by extension the capability to make a nuclear bomb. This policy was motivated by a conventional weapons superiority over its rival China, later focusing on Pakistan. While India built its first research reactor in 1956, the weaponisation of this programme quietly started in 1960, completing its first plutonium reprocessing plant by 1964.Bhabha Atomic Research CentrePlutonium Plant at Trombay. National Security Archive. 1964. India's nuclear programme can trace its origins to March 1944 and its three-stage efforts in technology were established by Homi J. Bhabha when he founded the nuclear research centre, the Tata Institute of Fundamental Research (TIFR) in Bombay.

Weaponisation of the nuclear programme in 1960 was widely due to the India's loss of the border war with China in 1962 that provided the Indian government a view that the development of nuclear weapons would deter the potential Chinese influence towards its northern territories. By the U.S. intelligence estimates in 1964, India was in a position to develop nuclear weapons. Prime Minister Lal Bahadur Shastri opposed developing nuclear weapons due to fear of economic isolation but fell under intense political pressure, including elements within the ruling Indian National Congress. India was also unable to obtain security guarantees from either the Soviet Union or the United States in case of conflict with China. As a result, Shastri announced in 1966 that India would pursue the capability of what it called "peaceful nuclear explosions" that could be weaponised in the future.

In 1974, India carried out a surprise test of "crude design" of a nuclear bomb (code-named "Operation Smiling Buddha"), under Prime Minister Indira Gandhi, which the Indian government termed it as "peaceful nuclear explosion". The test used plutonium produced in the Canadian-supplied CIRUS reactor, and raised concerns that nuclear technology supplied for peaceful purposes could be diverted to weapons purposes. This also stimulated the early work of the Nuclear Suppliers Group.India Profile. Nuclear Chronology 1974–1975. Nuclear Threat Initiative. 2006. During the 1970s and the 1980s, the fear of international sanctions, economic isolation, and priortising the relations with the United States forced and refrained the successive governments of prime ministers Indira Gandhi, Morarji Desai, and Rajiv Gandhi towards further weaponising the nuclear programme beyond the approved civilian limits. This fear was evident when Indira Gandhi turned down the "weaponisation proposal" from the Defence Research and Development Organisation (DRDO) in 1982 but the approval was given towards the development of guided missile programme that would be developed into the deliverable nuclear payloads. India also supported international nuclear non-proliferation and arms control efforts.

After the military standoff with China in 1986 and the military standoff with Pakistan in 1987, Prime Minister Rajiv Gandhi reassessed the Indian strategic calculations and eventually asking his Defence Secretary Naresh Chandra to re-weaponise the nuclear programme which the successive Indian governments aggressively continued in the throughout the early 1990s. Around 1997, India most likely completed the weaponisation of its nuclear programme and moved it towards weapons testing 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 waived and lifted.

Development and weapon designs takes place on Bhabha Atomic Research Centre (BARC), a sole weapons development centre for Indian nuclear weapons.

India's no-first-use policy India has a declared nuclear no-first-use policy and is in the process of developing a nuclear doctrine based on "credible minimum deterrence." In August 1999, the Indian government released a draft of the doctrine which asserts that nuclear weapons are solely for deterrence and that India will pursue a policy of "retaliation only". The document also maintains that India "will not be the first to initiate a nuclear first strike, but will respond with punitive retaliation should deterrence fail" and that decisions to authorize the use of nuclear weapons would be made by the Prime Minister or his 'designated successor(s)'. According to the NRDC, despite the escalation of tensions between India and Pakistan in 2001–2002, India remained committed to its nuclear no-first-use policy.

India's Strategic Nuclear Command was formally established in 2003, with an Indian Air Force officer, Air Marshal Tej Mohan Asthana, as the Commander-in-Chief. The Joint Services SNC is the custodian of all of India's nuclear weapons, missiles and defense assets. It is also responsible for executing all aspects of India's nuclear policy. However, the civil leadership, in the form of the CCS (Cabinet Committee on Security) is the only body authorised to order a nuclear strike against another offending strike. 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.NSA Shivshankar Menon at NDC (Speech) : india Blooms 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.

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". Later he clarified that this was his personal opinion. Defence Minister Rajnath Singh in 2019 said that in the future, India's no-first-use policy might change depending upon the "circumstances". In a January 2022 statement, however, the Ministry of External Affairs reiterated India's doctrine of "maintaining a credible minimum deterrence based on a No First Use posture and non-use of nuclear weapons against non-nuclear weapon states".

As of 2025, India's no-first-use policy is qualified. It states that it will not engage in first use of nuclear weapons except in the event of "a major attack against India, or Indian forces anywhere, by biological or chemical weapons.

Indian nuclear triad

India's nuclear triad is a military force structure that includes three parts:

Intercontinental ballistic missiles (ICBMs): Land-based nuclear missiles