Strategic dependency is reliance on external suppliers, platforms, or infrastructure that is hard to replace quickly and can become a security and resilience risk. In cyber security, this matters when a critical service, software component, cloud provider, identity system, or AI model sits outside your direct control. If that dependency fails, is compromised, or changes terms, the impact can spread across many systems at once.
Attackers often target strategic dependencies because they create leverage: a single supplier breach, poisoned update, or outage can affect many downstream victims. Defenders reduce the risk by mapping critical dependencies, checking supplier security, diversifying where possible, using backups and fallback procedures, and limiting trust with strong access controls and validation. The goal is not zero dependence, but dependency that is visible, tested, and manageable.