Michael Stimson, co-founder of the Stimson Center, has written a valuable paper Pakistan’s Nuclear Strategy and Deterrence Stability, in which he concludes:

Pakistan’s [nuclear-weapons] stockpile is likely to grow as long as key constituencies within the country view their nuclear programs as a success story, domestic critics can be easily dismissed, relations with India remain contentious, and the sense of Pakistan’s international isolation grows.

As for India …

The central purpose of Pakistan’s nuclear arsenal, as defined by those who set nuclear requirements, is to protect Pakistan from a predatory neighbor that seeks either its demise or its submissiveness. … This widely held view within military circles remains fixed, even as Pakistan has become increasingly peripheral to India’s national ambitions. To acknowledge that a “hegemonic” neighbor has more pressing interests than to punish Pakistan would only magnify a sense of Pakistan’s national decline.

Indeed …

Indian elites resent being compared to Pakistan because, by almost every indicator, Pakistan is receding in India’s rear-view mirror.

Let me get this straight. Pakistan maintains and expands its nuclear-weapons program out of a need to believe that it’s a priority of India to invade, or at least retaliate with harsh measures, for extremist attacks, such as Mumbai, that Pakistan has failed to prevent? In other words Pakistan has locked itself into enacting this charade that’s not only prohibitively expensive but threatens its own existence because the bottom might drop out of its national pride if it wasn’t foremost in the minds of India as a threat?

That’s a high price to pay for a case of low self-esteem.