the term "retreater" and advocated relocating to a rural retreat when society breaks down. Writers such as Howard Ruff warned about socio-economic collapse and recommended moving to lightly populated farming regions, most notably in his 1979 book How to Prosper During the Coming Bad Years, a best-seller in 1979. For a time in the 1970s, the terms "survivalist" and "retreater" were used interchangeably. The term "retreater" eventually fell out of favor. This was attributed to the United States withdrawal from Vietnam, which led to the perception that the country was less at risk of being attacked. People began to become interested again as public paranoia intensified over the Soviet threat during Cold War period. One of the most important newsletters on survivalism and survivalist retreats in the 1970s was the Personal Survival ("P.S.") Letter (circa 1977-1982) published by Mel Tappan, who also authored the books Survival Guns and Tappan on Survival. The newsletter included columns from Tappan, as well from Jeff Cooper, Al J. Venter, Bill Pier, Bruce D. Clayton, Rick Fines, Nancy Mack Tappan, J. B. Wood, Dr. Carl Kirsch, Charles Avery, Karl Hess, Eugene A. Barron, Janet Groene, Dean Ing, Bob Taylor, Reginald Bretnor, C. G. Cobb, and several other writers, some under pen names. The majority of this newsletter revolved around selecting, constructing and logistically equipping survival retreats. Following Tappan's death in 1980, Karl Hess took over publishing the newsletter, eventually renaming it Survival Tomorrow. 1980s Survivalist retreat books of the 1980s were typified by the 1980 book Life After Doomsday by Bruce D. Clayton, advocating survival retreats in locales that would minimize fallout, as well as specially constructing blast shelters and/or fallout shelters that would provide protection in the event of a nuclear war. 1990s Several books published in the 1990s offered advice on survival retreats and relocation. Some influential in survivalist circles are Survival Retreat: A Total Plan For Retreat Defense by Ragnar Benson, Strategic Relocation—North American Guide to Safe Places by Joel Skousen, and The Secure Home, (also by Skousen). 2000 to present In recent years, advocacy of survivalist retreats has had a strong resurgence after the terrorist attacks on the World Trade Center in New York City in 2001, the 2002 attacks and 2005 attacks in Bali, the 2004 Madrid train bombings in Spain, and the 2005 public transportation bombings in London. Several books published since 2000 advocate survival retreats and relocation. Some