This book develops a national economic impact model to estimate the effects of simulated terrorist attacks and natural disasters on individual US States and economic sectors. The model, called NIEMO (The National Interstate Economic Model) looks at interindustry relationships and interregional trade. It is highly disaggregated making the model very accurate. The authors examine potential attack targets including theme parks, sporting events, bridges and tunnels in the national highway system as well as attempts to shoot down airplanes or spread foot-and-mouth disease. Covered natural disasters are almost all real world: Hurricane Katrina, the Joplin Tornado, the Gulf Oil Spill and Hurricane Sandy. The effects on State economies caused by the closing international borders in response to a global pandemic is also examined.