# Defend Forward
**Domain:** Cyber strategy
**Doc Type:** Developed Doctrine Node
**Maturity:** Developed
**Collection:** [[collections/Gamification|Gamification Collection]]
## Definition
**Defend forward** is the U.S. Department of Defense cyber approach of disrupting or halting malicious cyber activity as close as practicable to its source, including through action outside U.S. networks.
## Significance
The doctrine shifts defense from perimeter protection toward anticipatory and externally situated action. In gamification terms, it contests the board where adversary preparation occurs rather than waiting for a scored loss at the defended boundary.
Its implications depend on legal authority, host-nation relationships, operational secrecy, attribution confidence, proportionality, and escalation. “Forward” is not a claim that every external network is a battlefield, and public doctrine does not establish the details of any particular operation.
## Sources
- U.S. Cyber Command, [Cyber 101: Defend Forward and Persistent Engagement](https://www.cybercom.mil/Media/News/Article/3198878/cyber-101-defend-forward-and-persistent-engagement/)
- U.S. Department of Defense, [2018 Department of Defense Cyber Strategy](https://media.defense.gov/2018/Sep/18/2002041658/-1/-1/1/CYBER_STRATEGY_SUMMARY_FINAL.PDF)
## Routes
[[wiki/Persistent Engagement|Persistent Engagement]] · [[wiki/Gray Zone|Gray Zone]] · [[wiki/Escalation Ladder|Escalation Ladder]]