These authors have written a fascinating and well documented history of UFOs. It informs the reader of the evidentiary basis for many of the important sightings and the cultural context that prevailed during critical eras. It examines the political and psychological factors that influenced the way UFO's are regarded and the way this has shaped government policy. One of the great misfortunes is that a science of UFO's has never developed. The authors document how we might have had such a science if slightly different outcomes had occurred at selected historical tipping points. Instead we have no evidence-based science, government policies that insist that UFO's are not a national security problem despite evidence consistent with aerial surveillance functions, and a public that is treated like children and intentionally deprived of information to arrive at informed conclusions. It's all documented here.