No First Use (NFU)
A nuclear doctrine commitment in which a state pledges not to use nuclear weapons except in response to a nuclear (or in some formulations, chemical/biological) attack.
India’s NFU Policy
India’s 2003 nuclear doctrine makes NFU its first and most prominent commitment:
India will only use nuclear weapons in response to a nuclear attack on Indian territory or Indian forces anywhere.
The doctrine also extends a conditional warning to chemical/biological attacks. India will not use nuclear weapons against non-nuclear weapon states.
NFU is paired with Massive Retaliation — the promise that while India won’t strike first, any adversary that does strike first will face an overwhelming response designed to cause “unacceptable damage.” This combination is meant to make the NFU credible (you lose nothing by India not striking first) while making first-use against India irrational.
Why NFU is Unusual
Most nuclear states — including the US, Russia, France, and the UK — reserve the right to use nuclear weapons first, including in response to large conventional attacks or extreme existential threats. Only China and India among major nuclear powers have formal NFU doctrines.
The debate within India over NFU is ongoing: some strategists argue that NFU, combined with Credible Minimum Deterrence, is sufficient; others argue it constrains options and reduces deterrence credibility against Pakistan (which has a much smaller territory and a “first use if existence threatened” posture).
NFU and the Deterrence Logic
NFU only works if the retaliatory threat is credible despite the non-first-use pledge. This is why the nuclear-triad and second-strike survivability are critical complements to NFU — if an adversary knows India’s weapons can survive a first strike, the retaliatory threat remains real even under NFU constraints.