 "Defence")
When any two states with nuclear weapons engage in armed hostilities, a possible escalation to an exchange using nuclear weapons can never be ruled out. Therefore, in the India-Pakistan context, any conventional war will inevitably carry the seeds of a nuclear exchange.
Given their geographical proximity, no distinction is possible, indeed plausible, between their use of shorter-range theatre nuclear weapons and longer-range strategic weapons. Even a theatre nuclear weapon would result in massive destruction. What distinguishes a theatre weapon from a strategic one is the command-and-control mechanism applicable to the use of the weapon rather than its yield. If authority to launch the weapon is delegated to the theatre commander in the field rather than the central Nuclear Command Authority (NCA) , then the weapon may be classified as a theatre weapon. As far as one is aware, neither India nor Pakistan have delegated the use of any class of nuclear weapons to theatre commanders.
There is another important factor that characterises a possible nuclear exchange between India and Pakistan. Reaction time to a possible attack by nuclear weapons is extremely short, given the geographical proximity of the two countries. Command-and-control becomes much more challenging, particularly since several categories of delivery vehicles, whether missiles or aircraft, are of dual use; they can carry conventional as well as nuclear munitions. It is only upon impact that the nature of the weapon would become known. It is these ambiguities which act as a far greater deterrent against either side contemplating crossing the nuclear threshold. Let us hope that this continues to restrain both countries. India and Pakistan subscribe to different doctrines of nuclear use. India has maintained a posture of No-First-Use (NFU). It will use nuclear weapons only in response to a nuclear attack. This was later expanded to include retaliation against an attack by chemicals and biological weapons, both of which are classified as Weapons of Mass Destruction (WMD), just as nuclear weapons are. It was also clarified that retaliation would follow an attack with such WMD, not only against the territory of India but also against Indian armed forces operating outside the territory of India. This has expanded the ambit of the retaliation-only policy. India’s doctrine also asserts that any use of nuclear weapons against it would invite “massive retaliation” designed to inflict an unacceptable level of damage on the adversary. Thus, the Indian doctrine does not subscribe to the theory of “graduated response”, which was popularised during the Cold War years. This posture was eventually given up since it was realised that any level of nuclear exchange, once initiated, would inevitably escalate to the strategic level. A limited nuclear war is a contradiction in terms, and this should be borne in mind in the India-Pakistan context.
