I think we should--or at least, we should threaten to. And we should consider something similar for North Korea an Iran as well.
Before you go ballistic (or just dismiss this diary as the rantings of a bloodthirsty lunatic), hear me out--please!
From the WaPo:
Khan will essentially go unpunished for presiding over what Pakistani officials now acknowledge, after years of denials, was a far-reaching scheme to peddle hardware, blueprints and design assistance by means of a thriving nuclear black market stretching from the Persian Gulf to Southeast Asia.
[...]
According to investigators, Khan said he provided the assistance to Iran, North Korea and Libya to deflect international attention from Pakistan's nuclear program.
He also has maintained, according to a friend of Khan's and a senior investigator, that three army chiefs of staff, including Musharraf, were aware of the assistance he provided to North Korea in exchange for help with Pakistan's ballistic missile program.
So not only is Pakistan constantly teetering on the verge of becoming a nuclear-armed radical Islamist regime, it has been peddling the technology to some of the worst characters out there. And this guy Khan is getting off without even so much as a slap on the wrist.
I wish there were no such thing as nuclear weapons. But the genie's out of the bottle, and we have to live in the real world. However, there's a world of difference between regimes like China's (which--as awful as they are--show little likelihood of nuking anyone or giving nukes to terrorists or rogue states) and the horrendous mess in Islamabad. This state of affairs, if allowed to continue, threatens the lives of millions.
And beyond the obvious risks of massive levels of death, destruction/contamination, and radiation sickness and cancer, think of the chaos that would ensue if a few of the world's great cities (New York, London, Moscow) were hit by nuclear holocaust. Beyond the immediate social and economic displacement (that would make 9/11 pale by comparison), what do you suppose would happen in other big cities? Residents would scatter across the landscape, afraid to gather in concentrations that would make them future targets. Their diaspora, though it might rejuvenate some small towns, would put an incredible strain on the infrastructure and devastate the environment. The urban underclass might well remain in the cities, for lack of other options; but their economic situation would become even more desperate.
Civil liberties would become a distant memory. Draconian martial law would likely become de rigueur across the globe, as the world's superpowers freak out, carve the world into spheres of influence (though this could have the potential, ironically, to ignite an old-fashioned, rubble-bouncing, ICBM exchange), and clamp down hard on any group that could remotely be associated with terrorism. (Of course, that's also a perfect opportunity to take out one's political opponents, as we Democrats can imagine all too well.)
So keep this nightmarish scenario in mind as I argue, essentially, that "an ounce of prevention is worth a pound of cure".
What we should do:
Go to the Security Council (perhaps in closed session) and try to enlist the cooperation (or at least, noninterference) of the other nuclear superpowers. All are threatened by nuclear proliferation.
Issue an ultimatum to Pakistan. They must turn over all their nukes, scrap their programs, and allow the continual oversight of nuclear inspectors (including watching the scientists 24/7). Or else. (Oh, and let us come in and look for Osama while we're at it.) The "carrot" part of the package could include economic aid, maybe even supplying conventional weapons like tanks and planes as a sort of compensation.
Similar "offers" should be extended to Iran and perhaps North Korea (depending on whether or not they have crossed the threshold to a capability of delivering ICBM nukes to American cities, which puts them in the "too late" category).
Furthermore, the nuclear powers need to be more vigilant and uncompromising about proliferation. The world's uranium mines should be placed under heavy guard, under the control of the SC. All the world's enriched uranium and plutonium needs to be precisely inventoried and better guarded. And though in general I am very reluctant to put any controls on the dissemination of knowledge, I think the methodology of producing WMDs needs to be an exception. It should be illegal worldwide to teach this information in universities or otherwise promulgate it, except in top-secret military academies (and anyone who becomes a nuclear scientist would agree to give up, for life, a certain measure of civil liberties--they should be subject to constant surveillance).
Yes, a lot of this sounds harsh, and I myself don't relish the notion of taking such extreme measures. But, again: consider the alternative.