Levels of Pakistan's Nuclear Threshold
The doctrine is not the part of the Minimum Credible Deterrence principle of Pakistan, however, the doctrine is integrated the nuclear dimension into its defence principle. According to the sources (after being obtained from Pakistan's nuclear command authority) published by the International Institute for Strategic Studies (IISS), the definition of four potential thresholds has been refined in the form of four thresholds which were first mentioned by officials at the nuclear command authority in late 2001.
Spatial Threshold:
The armed and military penetration of Indian Armed Forces into Pakistan on large scale may elicit a nuclearize massive retaliation, if and only if the Pakistan Army is unable to stop such intervention. For instance, many analysts, including some Indians, believe that the Indus Valley the "lifeline" of Pakistan is one of many other "red lines" that Indian forces should not cross. The capture of key objectives in this crucial northeastsouthwest axis might well provoke nuclear retaliation by Pakistan.
Military Threshold:
The complete knockout or comprehensive destruction of a large part of Pakistan Armed Forces, particularly and most importantly the Pakistan Air Force (PAF), could lead to a quick nuclear response if Islamabad believed that it was losing the cohesiveness of its defence and feared imminent defeat. A senior ranking PAF officer maintained that "orders given to PAF (and its missile command) are identical to the guidelines given to the NATO commanders during the Cold war crises. This criterion is even more important for the Pakistan Armed Forces because of its critical role in maintaining the countrys stability. As noted above, an attack on a nuclear installation has also been posited as a threshold. According to PAF, this level of threshold also included the chemical or biological weapons attack against Pakistan, would also respond to massive retaliation.
Economic Threshold
This level implicitly and explicitly refers for the countermeasure operations of Pakistan Navy. The economic strangulation and economic blockade is also a potential threat to Pakistan, in which if Pakistan Navy is unable to counter it effectively. This primarily refers to a potential Indian Navy blockade of Sindh Province and coastal cities of Balochistan Province, or the stopping of the Indus water flow. It could also refer to the capture of vital arteries such as the Indus.
Political Threshold
Finally, Pakistan's geostrategist, game theorists and political strategists and planners suggest that a destabilization of the country by India could also be a nuclear threshold if Islamabad has credible proves to believe that the integrity of the country were at stake. Stated scenarios are political destabilization or large-scale internal destabilization in which if Pakistan Marines (along with other paramilitary command) are unable to stabilized it effectively. One example would be encouraging the breakaway of one or more Pakistan's provinces.