This book covers many aspects of cyberspace, emphasizing not only its possible 'negative' challenge as a threat to security, but also its positive influence as an efficient tool for defense as well as a welcome new factor for economic and industrial production. Cyberspace is analyzed from quite different and interdisciplinary perspectives, such as: conceptual and legal, military and socio-civil, psychological, commercial, cyber delinquency, cyber intelligence applied to public and private institutions, as well as the nuclear governance.