However a report produced in 2015 by the Carnegie Endowment for International Peace and the Stimson Center asserts that Pakistan may be outpacing India in terms of its nuclear stockpile, and may possess 350 nuclear warheads in the next five to ten years. A 2016 SIPRI report confirmed the assessment that Pakistan has more nuclear warheads than India
However, what distinguishes the two neighbors' nuclear-weapons programs from each other is not so much the pace of production or the size of the stockpiles, but their radically different nuclear doctrines.
The major difference between the two countries' nuclear doctrines is that while India has renounced first use of nuclear weapons, Pakistan has refused to do so by reserving its right to use nuclear weapons in the face of India's conventional superiority.
So far, uncertainty regarding Pakistan's nuclear threshold is the principal factor preventing a major conflagration in South Asia. Pakistan's refusal to disavow first use of nuclear weapons, and its emphasis on amassing tactical nuclear weapons and short-range missiles as a corollary of its nuclear doctrine, can be explained in light of its conventional-force inferiority vis-à-vis India. It is in fact a mirror image of the American nuclear doctrine as applied to central Europe during the Cold War. The United States refused to disavow first use of nuclear weapons, and deployed tactical nuclear weapons in central Europe on a large scale, because of NATO's presumed inferiority in terms of conventional power vis-à-vis that deployed by the Warsaw Pact.