A declared nuclear posture under which a State commits not to use nuclear weapons first in a conflict, reserving them only for retaliation against a nuclear (or, in India's stated formulation, a major chemical or biological) attack on it or its forces.
NFU is a foundational element of India's nuclear doctrine; the 1999 draft, the 2003 review, the chemical and biological caveat, and the pairing with credible minimum deterrence are standard strategic-affairs facts.
NFU is a use posture, not a pledge to disarm; India keeps a capable arsenal. It is not the same as credible minimum deterrence (the size and survivability principle) but the two are complementary parts of the same doctrine.
India's pledge not to use nuclear weapons first (1999 draft, 2003 review), paired with credible minimum deterrence and assured massive retaliation.
concept credible minimum deterrence, concept second strike capability, concept strategic forces command, concept nuclear non proliferation treaty