MAD is not an effective means of maintaining world security. It relies upon states being too afraid to ever attack one another with nuclear weapons, but the risk of one doing so remains, irrespective of the doctrine. It has too many inherent risks and raises the very real chance, as weapons amass and proliferate, of their being used1. At the same time, should a nuclear weapon be used by a rogue state against another country, that country must have some means of retaliation. The problem is that the weapon likely to be used in such an attack will be crude and incapable of doing the sort of damage that a refined nuclear weapon of the Western nuclear powers could. This makes the question of what constitutes a proportional response difficult to answer. Should North Korea, for example, ever be able to attack the United States or its allies with nuclear weapons, its crude missiles will warrant a response, but quite possibly not a strategic nuclear missile-sized response. For this reason, the development of smaller, more versatile nuclear weapons makes these strategic considerations easier to manage, and allows for a range of responses left unavailable by the current blunt instrument of strategic nuclear missiles. 1 Sagan, Scott D. 1993. The Limits of Safety: Organizations, Accidents, and Nuclear Weapons. Princeton: Princeton University Press.