During his recent visit to Pokhran , Defence Minister Rajnath Singh argued that India's adherence to the principle of 'no first use' of nuclear weapons is not sacrosanct. As Singh stated to the media, "Pokhran is the area which witnessed Atalji's firm resolve to make India a nuclear power and yet remain firmly committed to 'no first use' doctrine. India has strictly adhered to this doctrine. What happens in future depends on the circumstances." Singh's comments, coming against the backdrop of recent Pakistani threats, have only intensified an already heated debate enveloping the future of India’s nuclear doctrine.A nuclear doctrine states how a nuclear weapon state would employ its nuclear weapons both during peace and war. By communicating to the enemy its stated intentions and resolve, nuclear doctrines help states to establish deterrence vis-à-vis its adversary during peace and once deterrence fails, guides the state’s response during war. After the 1998 nuclear test when India declared itself a nuclear weapon state, it also enunciated a doctrine of 'no first use' of nuclear weapons. Put simply, Indian decision-makers categorically rejected the idea of initiating the use of nuclear weapons in any conflict scenario. India’s nuclear doctrine was purely retaliatory in nature. New Delhi would avail the nuclear option only in case it was attacked first. But once attacked, India’s response would be massive. Since then, for almost two decades, ‘no first use’ has remained a core organizing principle of India’s nuclear deterrence.Lately, however, the sanctity of 'no first use' has been called into question not only by strategic analysts but also high-ranking government officials. In 2016, then defence minister Manohar Parrikar raised doubts on India’s adherence to the policy of 'no first use' by saying that New Delhi cannot "bind itself" to 'no first use' for eternity. Whereas political leaders have tried to insert an element of ambivalence into India’s nuclear doctrine, retired government officials have been far more categorical.Lt. Gen. BS Nagal, a former strategic forces commander, has been consistently arguing for revocation of the NFU pledge on the grounds that it allows Pakistan to take the initiative while restricting India’s options. Militarily, ‘no first use’ puts India in a disadvantageous position. Amb. Shivshankar Menon, former National Security Advisor, has written that India may have to resort to first use in case it has definitive information on Pakistan’s intent to launch first. Pakistan’s low nuclear thresholds and its policy of using its nuclear umbrella to foment sub-conventional conflict in India is the principle reason behind the debate around India’s ‘no first use’ policy.The case to revoke the NFU pledge has also been made keeping in mind India’s other nuclear adversary: China. Given the increasing asymmetry of conventional military power between the two countries, some analysts believe that India should revoke its “no first use’ policy. Where India’s fails to deter China conventionally, it should leverage its nuclear capability.Yet, revoking the NFU would have its own costs. First, India’s image as a responsible nuclear power is central to its nuclear diplomacy. Nuclear restraint has allowed New Delhi to get accepted in the global mainstream. From being a nuclear pariah for most of the Cold War, within a decade of Pokhran 2, it has been accepted in the global nuclear order. It is now a member of most of the technology denial regimes such as the Missile Technology Control regime and the Wassenaar Arrangement. It is also actively pursuing full membership of the Nuclear Suppliers Group . Revoking the ‘no first use’ pledge would harm India’s nuclear image worldwide.Parting away with NFU would also be costly otherwise. A purely retaliatory nuclear use is easier to operationalize. Nuclear preemption is a costly policy as it requires massive investment not only in weapons and delivery systems but also intelligence, surveillance and reconnaissance (ISR) infrastructure. The latest estimates of India’s nuclear weapons by the Bulletin of Atomic Scientists point to a small arsenal of 130-150 nuclear warheads even though it has enough militarygrade plutonium to produce 200 warheads.In fact, when compared with the estimates a decade earlier of 70 nuclear warheads, there has only been a modest increase in India’s nuclear inventory. If India does opt for first use of nuclear weapons and given that it has two nuclear adversaries, it would require a far bigger inventory of nuclear weapons particularly as eliminating adversaries’ nuclear capabilities would require targeting of its nuclear assets involving multiple warheads. The controversy around the supposed low yield of its Hydrogen weapon test in 1998 further complicates this already precarious calculation.Similarly, first use of nuclear weapons would require a massive increase in India’s nuclear delivery capabilities. There is yet no evidence suggesting that India’s missile production has increased dramatically in recent times. Moreover, India is yet to induct the Multiple Reentry Vehicle (MRV) technology in its missiles, which is fundamental to eliminating hardened nuclear targets. Finally, India’s ISR capabilities would have to be augmented to such a level where India is confident of taking out most of its adversary’s arsenal. According to a senior officer who had served in the Strategic Forces command , this is nearly an “impossible task”. Finally, India would have to alter significantly its nuclear alerting routine. India’s operational plans for its nuclear forces involve a four-stage process. Nuclear alerting would start at the first hints of a crisis where decision-makers foresee possible military escalation. This would entail assembly of nuclear warheads and trigger mechanisms into nuclear weapons. The second stage involves dispersal of weapons and delivery systems to pre-determined launch positions. The third stage would involve mating of weapons with delivery platforms.The last and final stage devolves the control of nuclear weapons from the scientific enclave to the military for their eventual use. Canisterization of missiles has combined the dispersal and mating of weapons into a single step, cutting down the effort required for achieving operational readiness. Even then, this model does not support first use of nuclear weapons as it gives ample warning to the adversary of India’s intentions. There is certainly a need for a reappraisal of India’s nuclear doctrine.All doctrines need periodic reviews and India’s case is no exception. Given how rapidly India’s strategic environment is evolving, it is imperative to think clearly about all matters strategic. But if Indian policymakers do indeed feel the need to review the nation’s nuclear doctrine, they should be cognizant of the costs involved in so doing. A sound policy debate can only ensue if the costs and benefits of a purported policy shift are discussed and debated widely.