Book excerpt: The use of atomic energy for military purposes has given rise to a variety of nuclear accidents from the outset. This applies to all levels of use: from the manufacture of weapons to their commissioning. This book provides an overview of the potential impact of such accidents. The prospective consequences of local and global nuclear war are detailed. Similarly, for each accident, the environmental, ecological, health and socio-economic consequences are reviewed. The contamination of the environment and its fauna and flora is detailed and the effects of ionizing radiation are reported. The same is provided for human populations and the adverse effects on the health and physical and mental states of the populations concerned. The economic cost of accidents is also evaluated. The research presented in this book is based on scientifically recognized publications, and reports from the military forces of the various countries concerned and from the national and international organizations competent in this field (IAEA, WHO, UNSCEAR, IRSN, ICPR, etc.).