Pakistan's atomic arsenal probably consists of between 90 to 110 nuclear warheads, a latest Congressional report has said, informing the American lawmakers that Islamabad is interested in concluding a nuclear cooperation deal with the US, which would require their approval.
"Pakistan's nuclear arsenal probably consists of approximately 90-110 nuclear warheads, although it could be larger," said the report of the Congressional Research Service, an independent research wing of the US Congress.
"Islamabad is producing fissile material, adding to related production facilities, and deploying additional delivery vehicles. These steps could enable Pakistan to undertake both quantitative and qualitative improvements to its nuclear arsenal," the report said.
India currently has approximately 60-80 nuclear weapons, it said, referring to one public estimate.
"Whether and to what extent Pakistan's current expansion of its nuclear weapons-related facilities is a response to the 2008 US-India nuclear cooperation agreement is unclear. Islamabad does not have a public, detailed nuclear doctrine, but its 'minimum credible deterrent' is widely regarded as designed to dissuade India from taking military action against Pakistan," it said.
"It is worth noting that Pakistani officials have expressed interest in concluding a nuclear cooperation agreement with the United States, which would require congressional approval," said the report titled 'Pakistan's Nuclear Weapons: Proliferation and Security Issues'.
Noting that Pakistan has in recent years taken a number of steps to increase international confidence in the security of its nuclear arsenal, the report however said instability in Pakistan has called the extent and durability of these reforms into question.
"Some observers fear radical takeover of a government that possesses a nuclear bomb, or proliferation by radical sympathisers within Pakistan's nuclear complex in case of a breakdown of controls. While US and Pakistani officials continue to express confidence in controls over Pakistan's nuclear weapons, continued instability in the country could impact these safeguards," it said.
Observing that Pakistan appears to be increasing its fissile production capability and improving its delivery vehicles in order to hedge against possible increases in India's nuclear arsenal, the CRS report said Islamabad may also accelerate its current nuclear weapons efforts.
The Congressional report running into nearly 30 pages informs lawmakers that in addition to making qualitative and quantitative improvements to its nuclear arsenal, Pakistan could increase the number of circumstances under which it would be willing to use nuclear weapons.
"For example, Peter Lavoy has argued that India's efforts to improve its conventional military capabilities could enable New Delhi to achieve technical superiority in intelligence, surveillance, and reconnaissance, as well as precision targeting, providing India with the capability to effectively locate and efficiently destroy strategically important targets in Pakistan," it said.
"Islamabad could respond by lowering the threshold for using nuclear weapons, according to Lavoy. Indeed, a Pakistan foreign ministry spokesperson warned in May 2009 that Islamabad could take this step... The Pakistani government may also consider fielding non-strategic nuclear weapons in order to increase the credibility of its nuclear deterrent versus Indian conventional military operations," the CRS report said.
According to the report, Pakistan has two types of delivery vehicles for nuclear weapons: aircraft controlled by the Pakistan air force and surface-to-surface missiles controlled by the Pakistan army.
Pakistan could deliver its nuclear weapons using F-16 fighter aircraft purchased from the United States, provided that modifications are made. It is widely believed that Islamabad has made the relevant modifications to the F-16s previously sold to them by Washington, it added.