This, the outcome of a Defense Department study led by author Clark, is a timely, hard-headed, non-inflammatory account of America's vulnerability to preemptive nuclear strike, terrorism, sabotage, and economic pressure. In Part I the authors present a scenario for a limited nuclear war (assuming, as the military does, that such is possible), and show that our current overcentralized system of power generation is perilously exposed to a knockout blow. America is also dangerously dependent on oil from unstable regions of the globe, and our large nuclear reactors are sitting ducks for missiles, terrorists, or saboteurs. Present plans for civil defense are totally unworkable, say the authors, and attempts to adopt the Swiss or Russian systems would squander billions to little practical effect. Our strategy, then, must be to decentralize as rapidly as possible (thus also providing realistic civil defense options on the local level). Part II offers blueprints for switching central power complexes over to small, dispersed local systems (which would be cheaper and more efficient). Alternative power sources--solar, water, biomass, geothermal, wind--are critically evaluated and linked to feasible industrial strategies such as power cogeneration, heat pumps to recover waste heat (vast savings are possible), the introduction of fuel-efficient technologies (the Japanese and Germans are already running prototype 100-mpg vehicles), and a halt to government subsidies of the nuclear industry (which must be redesigned to the small-and-dispersed pattern). Much of Part II is, indeed, what responsible conservationists have been promoting for years; but the schemes and recommendations detailed here, relevant to everyone but aimed specifically at the hawks, jingoists, and advocates of monolithic industrial blocs, deserve the widest possible dissemination.