Although I use the term Complexity Theory as if it was a coherent
body of scientific theory, this area of research is in fact still
both young and evolving. I use it therefore as a shorthand
term to cover a number of areas, each with its own distinct
heritage. Broadly, it covers fractal structures, nonlinear
dynamical systems, and models of self-organisation and self￾organised criticality.
The research on which this book is based could not have been
carried out without the help of a number of other people.
Their contributions are, I hope, suitably acknowledged in the
text. I would like to thank particularly Walter Perry (RAND),
Susan Witty (Dstl), David Rowland, and Maurice Passman for
their contributions. I am also most grateful to Professor Henrik
Jensen for contributing the Foreword