This book addresses the likely effects of the CTB on nuclear weapon programmes and decision making in the nuclear weapon states, the threshold states and the non-nuclear weapon states of proliferation concern. The book concludes that, while some states will indeed maintain their nuclear weapon arsenals and options under the CTB and one or two may even undertake some modernization, the CTB will foreclose a number of technologies to all three groups of states and will probably be signed and ratified by all of them. Further, the CTB will codify a norm against nuclear modernization and strengthen the norm against nuclear proliferation in a way that reinforces other efforts to restrict nuclear activities. The book elucidates the significance of treaty provisions that will be included to accommodate existing stockpiles or options and their significance as possible modernization or proliferation loopholes.

It closes with a review of practical steps that can be taken, unilaterally and multilaterally, to further strengthen these norms and reinforce the CTB regime.