How is it that, in doing our very best to achieve one thing, we can end up achieving just the opposite? There exists an unseen force with an unassuming name that conceals all manner of terrors. It is `Unintended Consequences', and it takes our efforts to do the good and right thing, turns them to ashes and blows them back in our faces. Whether it be governments fighting a "War on Terror" only to bring their economies crashing about their ears, ecologists attempting to stamp out pests but making things ten times worse in the process, or giving people lots of choice only for them to make worse decisions, it is all too easy to start out with the best of intentions, only to end up doing more harm than good. In Unintended Consequences, Clive Wills discusses national disasters, Prohibition and the War on Drugs, frustrated efforts to improve health and safety, and touches on issues of everyday life such as how to improve relationships and bring up children. As HL Mencken reflected, "For every complex problem, there is a solution that is simple, neat, and wrong". This book examines the many ways in which those apparently simple solutions can turn around and bite us, and more importantly, just what we can do about it.