The Nuclear doctrine of Pakistan is a theoretical concept of military strategy that promotes deterrence by guaranteeing an immediate "massive retaliation" to an aggressive attack against the state. Pakistan's foreign minister Shamshad Ahmad had warned that if Pakistan is ever invaded or attacked, it will use "any weapon in its arsenal" to defend itself. Persuasion for Effect A doctrine is divided into four different thresholds before the weapons would become operationally activated during a conventional or nuclear war with an aggressor state. In the event of war, for instance war between India and Pakistan, the Indian Armed Forces' numerical superiority and large stock of conventional weaponry is most likely to overwhelm Pakistan. Therefore, in a deteriorating situation, where an Indian military aggression is more likely to penetrate through Pakistan's defenses (or has already breached the main defense line causing a major setback to overall defense) which cannot be reversed by conventional means, the government would be left with no other option except to use nuclear weapons to stabilize the situation, with a first strike. The rationale behind the doctrine is to prevent India from any military intervention (both conventional and surgical) that would lead to the disintegration of the country, as it did in 1971 (see Indo-Pakistani war of 1971). The South Asian affairs expert, Professor Stephen P. Cohen terms the strategy of Pakistan an "option-enhancing policy". According to sources, the doctrine entails a stage-by-stage level of advancement in which the nuclear threat is increased at each step to deter India (or any aggressor state) from attacking: A public or private warning. A demonstration atomic test of a small atomic device on its own soil. The use of (a) nuclear weapon(s) on Pakistan's soil against foreign attacking forces. The use of (a) nuclear weapon(s) against critical but purely military targets on foreign soil, probably in thinly populated areas in the desert or semi-desert, causing the least collateral damage. This is possibly to prevent a retaliation against Pakistani cities. Levels of threshold The doctrine is not part of the Minimum Credible Deterrence principle of Pakistan, however, the doctrine is integrated the nuclear dimension into its defence principle. According to the International Institute for Strategic Studies (IISS), the definition of the four potential thresholds has been refined from the first thresholds which were mentioned by officials at the Pakistan nuclear command authority in late 2001. Spatial threshold - The military penetration of