Introduction 3

PART I: Conceptual Foundations: How Systemic Shocks Affect Societies 6

 Systemic Risk and Cascading Disasters 10

 Complex Systems, Tipping Points, and Non-Linear Change 12

 Critical Social Systems and Civilizational Collapse 13

 Environmental Stress as a Systemic Shock 14

PART II: Mechanisms of Cascading Disruption Relevant to Nuclear War 17

 Environmental Disruption as the Initiating Systemic Shock 19

 Clean Water Disruption 22

 Food System Disruption 23

 Economic and Trade Network Disruption 24

 Migration and Demographic Pressures 26

 Governance Stress and Institutional Fragility 28

Composite Shock 29

Implications for Risk Reduction 32

Conclusion 35