This book calls for the progressive creation of supra-national institutions intended to protect life on Earth against natural threats, be these terrestrial (pandemics, super-volcanoes, major earthquakes) or celestial (comets, asteroids, meteor storms). The protection proffered would need to be pre-emptive though also responsive, reducing the number of adverse events but also their specific consequences. Rancid though the world scene currently looks, this may actually be a good time to look towards a planetary security programme that can build up over a century or more. It would need special international institutions that are sufficiently integrated to cope with the celestial and terrestrial contingencies anticipated yet not so much a class apart as to be a law unto themselves, a military regime able to ride roughshod over general world opinion. Such an holistic approach to planetary security might prove to be a definitive substitute for war between nations. Professor Brown comes to such questions from a broad career background. His lead qualifications are a Masters degree from Oxford in Modern History and a Doctorate of Science from Birmingham (UK) in Applied Geophysics. He has been a naval meteorologist; staff college instructor; part-time but pro-active as a defence correspondent for several of the West's leading journals; and political consultant. From 1980 to 1986, he was Chairman of the Council for Arms Control. From 1993 to 1997 he worked half-time in the Sensors and Electronic Systems directorate of Britain's Ministry of Defence. This was as the Academic Consultant in a small task force specifically created to advise the government of the day apropos what British policy to Strategic Ballistic Missile Defence should be. A declassified rendering of his 90,000-word report (published by Mansfield College, Oxford, in 1998) argued firmly against our going down this path. It could lead to a catastrophic arms race.