Cascading supply disruptions—triggered by shocks in energy, transport, labor, or geopolitical systems—pose systemic threats to food security, health systems, critical infrastructure, and global trade. Accurately forecasting these disruptions requires early signals that cut across sectors, time zones, and data domains. This question invites expert input on the most reliable, scalable, and actionable indicators of imminent supply chain failures. Suggested areas include satellite monitoring of port activity, financial market volatility, cyberattack telemetry, climate anomaly detection, and predictive analytics using trade flow or inventory data. The goal is to identify a high-impact set of cross-sector early warning inputs for integration into global observability systems.