
1
Chapter 1
Introduction
1.1 Background
Before reading the chapters of this book, the rst question that should be asked
is “Why is risk acceptability analysis (RAA) crucial for critical infrastructure secu-
rity and defense against terrorism and disaster?” Most experts are aware that risk
is dened as a function of the probability of adverse events and dangerous conse-
quences. Risk of terrorist acts is measured according to the perceived magnitude of
grave consequences and the realized relative weight associated with the probable
occurrence of the event by society. Hence, risk assessment is routinely employed by
security and defense professionals ...