This book is a study of the single most controversial issue arising in the single most important ongoing international arms control negotiation. The topic is the comprehensive nuclear test ban treaty (CTB) talks, and the core question concerns the likely 'scope' of the ultimate agreement: precisely which types of nuclear weapons-related events would be bared, and which would be preserved as legal, under a sound widely-acceptable, treaty?

Weapons engineers in the United States, Russia, and elsewhere have created a range of ambiguous events some of which would help ensure the continuing 'reliability' of existing nuclear weapons, some of which would assist in the process of designing new genres of bombs, and some of which might be relevant to a range of wholly civilian activities, such as the production of fusion energy.

Diplomats (aided by military, technical, legal, and other experts) are now attempting to resolve these issues in the treaty negotiations and the international - and for many countries, internal - political machinations are complex, important, and protracted.