In this important study of the looming dangers of social and economic catastrophe, Homer-Dixon, a Canadian expert on the environment, security, and complex systems, argues that Western society faces a new and expanding array of challenges -- oil shortages, global warming, economic instability, megaterrorism -- that threaten to converge and reinforce one another, setting the stage for "synchronous failure" and the massive breakdown of our modern way of life. He uses the metaphor of an earthquake: a series of "tectonic stresses" are accumulating underneath the surface, made worse by global connectivity and the growing ability of small groups to project violence. The moment of upheaval is hard to predict, but if the stresses come together they will produce an impact greater than the sum of their parts. Homer-Dixon offers a striking vision of how to confront this world of risk and uncertainty, calling for "resilience-enhancing" strategies that protect food- and energy-supply networks and that can better cope with surprise. He effectively conveys the mentality necessary to operate in this new era but is less clear about the needed political innovations.