Which command must be coordinated with before taking action outside the Department of Defense (DoD)?

The correct answer is USCYBERCOM. This command is pivotal in coordinating operations and ensuring the security of cyberspace within the Department of Defense (DoD). When actions are proposed that will take place outside the DoD, especially in the realm of cyber operations, it is crucial to coordinate with USCYBERCOM to align with national policy, legal considerations, and operational security.

USCYBERCOM has overarching authority over military cyber operations, making it essential for any initiatives that could affect the cybersecurity landscape, including collaboration or engagement with external entities, whether governmental or private. This coordination helps ensure that the actions undertaken are consistent with DoD objectives and capabilities, while also safeguarding national interests in the cyber realm.

Other commands mentioned may have operational roles but do not hold the same level of responsibility and authority in cyber matters as USCYBERCOM does. For instance, USAF primarily focuses on air force operations, NAVYCOM on naval strategies, and USNORTHCOM on homeland defense and security in North America, which may not directly address the complexities of cyber operations outside the DoD.