At the onset of the twenty-first century, a substantial portion of politicians and citizens throughout the world believe and declare that their states are facing existential threats, whether domestic, external, or both. This perception is discerned in states categorized widely, from not democratic and partially democratic states to small states and greater powers that are considered to be democratic, such as the United States, Britain, and France. The chapters in this book present and further develop the major theoretical approaches to existential threats: structural, cultural, and rational. The authors also conceptualize existential threats and distinguish them from other types of threats, discussing some of the most important actors that promote the perception of an existential threat-the security sector especially (the military and the other security agencies), but also the media. Existential Threats and Civil Security Relations provides fresh comparative perspectives on a number of relevant cases, including small states that have faced-or still face-similar predicaments. These include effective democracies, such as the United States (in its formative period) and Switzerland; formal democracies, such as Israel and Finland; authoritarian or partially free states that have transformed into formal democracies, such as South Korea, Taiwan, South Africa, and the East European and Baltic states after the Cold War; and states that have remained partially free like Singapore and some formerly Soviet states.