The Concept May Now Constitute a Valid and Viable Response to Youth Unemployment, Soil Depletion, and the Impacts of Exogenous Disasters. It might, in several ''advanced'' countries, be implemented without costing governments or taxpayers a penny. The article discusses the intellectual and institutional history of the concept, and reviews the reasons for - and the considerable difficulties of - implementation. A new instrumentality to provide both jobs and training for the young will require political decisions at the highest level as well as a sweeping re-allocation of resources and a leadership cadre that is both astute and charismatic. Properly organized and led, the proposed Service could play a major role in re-interesting Third-World youth in the prospects offered by science and technology for a more prosperous and adventurous future, and thus contribute tangibly to the reduction of North-South tensions. Copyright (C) 1996 Elsevier Science Ltd