Washington, Aug 27 (PTI): Pakistan is on course of having about 350 nuclear weapons in about a decade, the world's third-largest stockpile after the US and Russia and twice that of India, two major American think-tanks said today.

"In the next five to 10 years Pakistan could have a nuclear arsenal not only twice the size of India's but also larger than those of the United Kingdom, China, and France, giving it the third-largest arsenal behind the United States and Russia," said a report by two renowned scholars Tom Dalton and Michael Krepon.

The 48-page report titled 'A Normal Nuclear Pakistan' by the Stimson Center and the Carnegie Endowment for International Peace says that the growth path of Pakistan's nuclear arsenal, enabled by existing infrastructure goes well beyond the assurances of credible minimal deterrence provided by Pakistani officials and analysts after testing nuclear devices.

"If Pakistan continues on its current path, and if there is no reassessment of its presumed need to compete effectively with India, in 10 years time Pakistan could possess a nuclear arsenal nearing 350 weapons (or at least a stockpile of fissile material sufficient for an arsenal of this size)," the report said.

"If Pakistan has defined production requirements for approximately 20 nuclear warheads annually against an India that competes haphazardly, it is unlikely to diminish annual production requirements for an India that competes seriously," it said.

Consequently, if New Delhi picks up the pace of this competition and Rawalpindi responds accordingly, Pakistan's future nuclear stockpile could grow well beyond 350 nuclear warheads.

"If deterrence fails, it appears that Pakistan has no intention of 'losing' a nuclear war with India," it said.

By staying on its present course, Pakistan faces very long odds against entering the nuclear mainstream, the report noted.

NSG members -- especially its non-nuclear-weapon state members -- are likely to view Pakistan's rapid growth in fissile material stocks and warheads as contrary to the norms of responsible nuclear stewardship, it said.

A nuclear future in which Pakistan seeks to exceed or at least match or offset the growth in India's nuclear and conventional military capabilities appears far bleaker for Pakistan than for India, the two think tanks said.

"Both countries have immense social needs, but by virtue of its faster-growing economy and expanding international trade, India has far more resources to devote to them," it said.

Maintaining such a large nuclear arsenal would come at a huge economic cost, the report said, adding that by staying on the present course, Pakistan's civilian and military leaders will face very hard budgetary decisions going forward.

"Pakistan's nuclear arsenal requires large mortgage payments within a baseline security budget (USD 7 billion) that officially consumes 2.8 per cent of Pakistan's GDP, but, is assuredly much higher," the report said.

According to published government documents, expenditures for atomic energy programmes this past year -- which may include some, but probably not all, of the activities related to Pakistan's nuclear weapons programme -- were roughly USD 650 million.

"With a growing population, major social and education requirements, severe energy shortfalls and rising needs, as well as requirements to bolster law enforcement and a judiciary that can stabilise Pakistan's internal security, Islamabad can ill-afford nuclear mortgage payments that will balloon in the decades ahead," the report said.

"These expenses will crowd out more pressing requirements to improve conventional armaments that military commanders are far more likely to use, whether in North Waziristan or elsewhere," it said.