Book excerpt: This book presents research into chemical, biological, radiological and nuclear (CBRN) defense and environmental security, exploring practical implications of the research. Contributions from a diverse group of international civilian researchers present the latest work on nanotechnology problems in this area, looking at detection, protective technologies, decontamination and threats to environmental security due to bacteriophages and nanomaterials. Highlights include the potential of Atomic Force Microscopy (AFM) to characterize the nanoscale properties of microbial pathogens, the development of bacteriophage-based therapeutics, prophylactic and diagnostic preparations and their uses in different fields, such as medicine, veterinary, agriculture, food and water safety, amongst others. Readers may also consider an inexpensive bioassay suited for assessing chemical poisoning in the environment such as the presence of pesticides, sensors to detect ultra-trace quantities of the explosive Pentaerythritol tetranitrate (PETN) using nanotubes and electrochemical sensors to simultaneously detect and reduce the explosive trinitrotoluene (TNT) to 2,4,6-triaminotoluene (TAT) in solution. This book shows how cooperative research among NATO countries and NATO partners can make a critical contribution to meeting the opportunities and challenges of nanotechnology problems relevant to chemical and biological defense needs. The papers presented here are representative of contributions made to the Advanced Research Workshop (ARW) on September 22-26, 2014 in Antalya, Turkey, to address the NATO SPS Key Priority of Defense against CBRN Agents and Environmental Security.