future. India first tested a nuclear device in 1974 (code-named "Smiling Buddha"), under Prime Minister Indira Gandhi as a 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. During the 1970s and the 1980s Prime Ministers Indira Gandhi, Morarji Desai, and Rajiv Gandhi opposed weaponizing its nuclear program beyond PNE's and theoretical research. In 1982, Indira Gandhi refused to allow the Defence Research and Development Organisation to develop active nuclear weapons, but also approved the Integrated Guided Missile Development Programme that would develop missiles to deliver a nuclear warhead if India developed one. India also supported international nuclear non-proliferation and arms control efforts. 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. Chandra continued the program through successive governments in the 1990s after Gandhi lost power in the 1989 general election. India most likely completed weaponized nuclear warheads around 1994. 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. Neutron bombs R Chidambaram, who headed India's Pokhran-II nuclear tests, said in a 1999 interview with the Press Trust of India that India is capable of producing a neutron bomb. 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 authorise 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