Pakistan has developed second strike nuke capability

Pakistan, which has kept open the option of first use of atomic weapons against 'nuclear-armed aggressors', has also developed a second strike capability, a Congressional report has said.

"Pakistan has reportedly addressed issues of survivability through second strike capability, possible hard and deeply buried storage and launch facilities, road-mobile missiles, air defenses around strategic sites and concealment measures," the Congressional Research Service (CRS) said in its report on Pak nuclear weapons dating May 15.

CRS is the research wing of US Congress, which prepares reports on issues of interest of the US lawmakers.

Pakistan has also pledged 'no-first-use' against non-nuclear-weapon states, but has not ruled out first-use against a nuclear-armed aggressor that attacks Pakistan - for instance, India.

Islamabad has time and again said that its nuclear weapons are targeted primarily towards India and are aimed to act as a deterrent against a larger neighbour.

"Analysts say this ambiguity serves to maintain deterrence against India's conventional superiority. Others argue that keeping the first-use option against New Delhi allows Islamabad to conduct sub-conventional operations, such as support for low intensity conflict or proxy war in Kashmir, while effectively deterring India at the strategic level," the CRS said.

"Pakistan reportedly stores its warheads unassembled with the fissile core separate from non-nuclear explosives, and these are stored separately from their delivery vehicles. Pakistan does not have a stated nuclear policy, but its 'minimum credible deterrent' is thought to be primarily a deterrent to Indian military action," the CRS report said.

"Pakistani and some US officials argue that Islamabad has taken a number of steps to prevent further proliferation of nuclear-related technologies and materials and improve its nuclear security," it said.

A number of important initiatives such as strengthened export control laws, improved personnel security, and international nuclear security cooperation programmes have improved the security situation in recent years.

However, 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," CRS said.

While US and Pakistani officials express confidence in controls over Pakistan's nuclear weapons, continued instability in the country could impact these safeguards, it said.