Plutonium and highly enriched uranium (HEU) are the basic materials used in nuclear weapons. Plutonium also plays an important part in the generation of nuclear electricity. Knowing how much plutonium and HEU exists, where and in which form is vital for international security and nuclear commerce. This book is a thorough revision of the World Inventory of Plutonium and highly Enriched Uranium, 1992. It provides a rigorous and comprehensive assessment of the amounts of plutonium and HEU in military and civilian programmes, in nuclear and non-nuclear weapon states, and in countries seeking to acquire nuclear weapons. The capibilities that exist for producing these materials around the world are examined in depth, as are the policy issues raised by them. Containing much new information, this book is indispensable to all those concerned with the great contemporary issues in international nuclear relations: arms reductions in the nuclear weapon states, nuclear proliferation, nuclear smuggling, the roles of plutonium and enriched uranium in the nuclear fuel-cycle, and the disposition of surplus weapon material.