Two days after Narasimha Rao’s body was cremated in 2004, an emotional Atal Bihari Vajpayee paid his old friend a startling tribute. Rao was the “true father” of India’s nuclear programme. Vajpayee said that, in May 1996, a few days after he had succeeded Rao as prime minister, “Rao told me that the bomb was ready. I only exploded it.”

“Saamagri tayyar hai,” Rao had said. (“The ingredients are ready.”) “You can go ahead.”

The conventional narrative at the time was that prime minister Rao had wanted to test nuclear weapons in December 1995. The Americans had caught on, and Rao had dithered – as was his wont. Three years later, prime minister Atal Bihari Vajpayee fulfilled his party’s campaign promise by ordering five nuclear tests below the shimmering sands of Rajasthan.

Vajpayee’s revelations unsettled this narrative with new questions.

How closely was Rao involved in India’s nuclear programme? What prompted his decision to test in December 1995? Why did he change his mind? Was it US pressure or something altogether more mysterious? Why did he pass on the baton to Vajpayee six months later?

The journalist Shekhar Gupta asked Rao these questions months before he died. The former prime minister patted his belly. “Arrey, bhai, let some secrets go with me to my chita [funeral pyre].”

On the morning of 15 December 1995, the New York Times ran a sensational story. “In recent weeks, spy satellites have recorded scientific and technical activity at the Pok[h]ran test site in the Rajasthan desert.” The story quoted US government officials telling The Times that American intelligence experts suspected India was preparing for its first nuclear test since 1974.

A few days after the leaked story, the American ambassador to India, Frank Wisner, sought a meeting with Rao’s principal secretary, Amar Nath Varma. Wisner walked into the PMO carrying photographs taken from American satellites. Varma told Wisner he had no idea what he was talking about. He asked Wisner if he could keep the photographs and show them to the scientists. Wisner quickly hugged the photographs. “These are part of my body,” he is reported to have angrily said. “The only way you can take the photographs is if you take me along.”

On 19 December 1995 – the day the nuclear tests had been originally scheduled – the Indian foreign minister Pranab Mukherjee (who was not in the loop on the nuclear tests) was asked by Rao to make a statement of denial. The Americans were not satisfied. That same day, the President of the United States, Bill Clinton, sent a message to New Delhi. He wanted to speak to the prime minister. Narasimha Rao asked his closest nuclear confidant to prep him on possible questions from Clinton.

The call came in the morning to Rao’s office in the PMO, sometime around 21 December. “I want to tell you about progress in the CTBT negotiations,” Clinton began. After speaking in generalities for a couple of minutes, Clinton moved sideways. “We are happy to note a clear statement by your foreign minister that the government of India is not testing.”

Rao replied as planned, “I saw the press clippings too. They are false.” “But Mr Prime Minister,” Clinton interjected, “what is this that our cameras have picked up?” Rao replied, again as planned. “This is only a routine maintenance of facilities.” Rao then added, slowly, so that Clinton could understand him through his Indian accent.

“There is right now no plan to explode. But yes, we are ready. We have the capability.”

The nuclear tests should have been conducted on 19 December. It is not known when Rao stopped it – at T-3 [three days in advance] or T-1 [one day in advance]. But here the matter rested until a few days after the Clinton phone call.

On 25 December 1995, a secret letter was delivered to Rao, asking him to delay testing for four weeks, to keep the US at bay. It went on to suggest that by early February 1996, India should conduct two to three nuclear tests. The note ended by quoting K Subrahmanyam: “India’s voice on nuclear disarmament is not heeded because it is like an elderly spinster espousing the virtues of chastity.”

Narasimha Rao ordered the bomb to be removed from the L-shaped shaft. Yet – contrary to the public narrative – he was far from done.

On 14 January 1996, Abdul Kalam wrote to Rao urging him to boycott the ongoing CTBT negotiations and test nuclear weapons as soon as possible. The note was prepared in consultation with other members of the secret nuclear committee. At 11 AM on 19 January 1996, Rao’s appointment diary shows that he met with his principal secretary, as well as his foreign, atomic energy and defence secretaries to “consider our stand on CTBT”. A month later, Rao asked the finance ministry to prepare yet another analysis of the economic effects of a nuclear test.

In late March, Rao received a second call from Bill Clinton. The US President once again urged Rao to desist from testing. It is not known what exactly Clinton said. But the very fact of the call is more evidence that Rao was actively considering testing nuclear weapons in March 1996.

National elections were scheduled for May 1996, and Rao spent the next two months campaigning. On 8 May at 9 PM, Abdul Kalam was asked to immediately meet with the prime minister. Rao told him, “Kalam, be ready with the Department of Atomic Energy and your team for the N-test and I am going to Tirupati. You wait for my authorisation to go ahead with the test. DRDO-DAE teams must be ready for action.”

Two days later, the election results were announced. Kalam recalls that Rao ordered him not to test, since “the election result was quite different from what he anticipated”. The BJP’s Atal Bihari Vajpayee took over as prime minister on 16 May 1996. Narasimha Rao, Abdul Kalam and R Chidambaram went to meet the new prime minister “so that”, in Kalam’s telling, “the smooth takeover of such a very important programme can take place”.

Vajpayee’s revelations of 2004 make clear what was discussed. Immediately afterwards, Vajpayee ordered nuclear tests, but rescinded that order when it was clear that his government would not last. In 1998, back as prime minister for the second time, Vajpayee was able to finally “go ahead” and explode.

The evidence is overwhelming that Narasimha Rao gave the “T-30” order to test nuclear weapons in late November 1995. Rao involved a large number of people in assessing the consequences, an unusual step for a man as secretive as he was. He knew that American satellites were hovering above Pokhran. They were nonetheless able to detect activity that indicated testing was imminent. US pressure followed, and Rao cancelled the tests.

It is also clear that India did not have a hydrogen or thermonuclear device in December 1995. A member of the nuclear committee confirms, “[This] became ready only by around March 1996.” Between April and May 96, Rao considered testing again. He backed off when he realised that he had lost the national elections.

Given that this is what we know, what can we deduce about Rao’s intentions? Only three theories fit the known facts.

The first is that Rao had decided to test nuclear weapons in December 1995. But the American satellites caught on, and under pressure from the US, Rao chose to postpone testing. This is the explanation favoured by nuclear expert George Perkovich in his book on India’s programme. This theory, however, does not explain why Rao decided to test again only a few months later. American pressure – and sanctions – would not have varied significantly between December 1995 and April 1996.

The second theory is that Rao never intended to test in December 1995, and the Americans were mistaken. “The truth is that Rao never cleared the tests,” journalist Raj Chengappa says in his superbly sourced book on the nuclear programme. This, however, leaves unexplained why Rao gave the order all the way till “T-7” in December 1995, and why he wanted to test again four months later. What game was Rao playing?

A third, more sensational, theory attempts an answer. Rao knew he had only one chance to test before sanctions kicked in, i.e., he could not both test conventional atomic bombs in December 1995 as well as the hydrogen bomb separately in April 1996. As Shekhar Gupta – who has had unprecedented access to Rao as well as the nuclear team – speculates: “By late 1995, Rao’s scientists told him that they needed six more months. They could test some weapons but not others…thermonuclear etc. So Rao began a charade of taking preliminary steps to test, without intending to test then.”

He then deliberately leaked the information on the tests – by telling many people about it, and ordering observable digging in Pokhran. When the Americans found out – as Rao wanted them to – he ordered the tests to end.

In doing so, Rao made India’s nuclear capacity clear while CTBT negotiations were ongoing, and gave his scientists breathing space to develop the hydrogen bomb. By April 1996, hydrogen bomb ready, Rao genuinely wanted to test, but decided against it since he had lost the mandate of the people.

For Rao to have gone ahead with this deception—only a whisker away from treason—there are three people he might have likely told: A.P.J. Abdul Kalam, R. Chidambaram and Naresh Chandra. Chidambaram and Chandra were both awarded the Padma Vibhushan, India’s second-highest civilian honour, by later governments. Kalam was given the Bharat Ratna and made President of India. Did Narasimha Rao tell his successors something about these men that the public does not know?

Regardless of which of these theories is true, they all point to the fact that far from dithering, Rao was actively involved in the nuclear programme – a trait he also exhibited on the economy, welfare schemes and foreign policy. The portrait that emerges is of a hands-on manager. As Arunachalam puts it, “I worked with five prime ministers. I would rate Rao very high. [He] was a rare politician who understood the importance of technology in building national policy.”

Rao’s magnanimity in letting Vajpayee revel in the glory of nuclear testing (including of the hydrogen bomb) is telling. As Abdul Kalam said, it “reveals the maturity and professional excellence of a patriotic statesman who believed that the nation is bigger than the political system”.

When India finally tested nuclear weapons in 1998, western sanctions followed. Yet – as Rao judged – it has not harmed India in the long term (its effects on India’s security is more contested). Subsequent prime ministers have also followed Rao in refusing to sign the CTBT and NPT.

In 2005, US President George W Bush decided to make an exception to the international non-proliferation regime. Under the Indo-US nuclear deal, India would separate its civilian and military nuclear facilities, placing only its civilian facilities under international scrutiny. The US would help with India’s civilian nuclear energy. The deal made India the only country not part of the NPT framework that is still allowed to do nuclear commerce with the rest of the world.

This deal would have been impossible had not India been both an acknowledged nuclear weapons state as well as an emerging economic power.

The 1998 nuclear tests – sanctioned by Vajpayee with the help of Narasimha Rao – forced the West to concede that India would never cap its nuclear programme. They could, of course, have treated India as a renegade – as they have Iran, North Korea, and to some extent, Pakistan. But the economic power of post-1991 India – for which Rao gets the lion’s share of the credit – meant that the West could not afford to alienate India. This mix of economic might and an unbending nuclear programme is what has led to new status for India in the international system.

Seen thus, Narasimha Rao is not just the “true father” of the 1998 nuclear tests. He is also the crafter of a fresh vision for India in the world. This new self-image, at odds with Nehruvian idealism, emphasises economic muscle alongside a conventional military and large nuclear programme. It is a vision not without its critics. But for better or for worse, it is likely to be the dominant way in which India sees itself in the years to come.

Excerpted with permission from Half Lion: How PV Narasimha Rao Transformed India, Vinay Sitapati, Penguin Viking.