A terrorist attack in a major city using an RDD or an IND could result not only in the loss of life but also have enormous psychological and economic impacts. Major cities are assumed to be preferred targets of such attacks, and local governments, along with their states, have primary responsibilities for early response (within the first 24 hours), with assistance from federal sources, as necessary, coming later. A disjointed or untimely response could increase the impact and undermine public confidence in federal, state and local governments' ability to respond to an attack. This book provides background for understanding the RDD threat and responses, and presents issues for Congress.