Question: I was able to read about cyber-warfare and how the United States regularly uses the term. However, the term is said to [still be ambiguous](https://en.wikipedia.org/wiki/Cyberwarfare#Definition) with the former Cyber Security Coordinator for the Obama Administration saying that

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> "there is no cyberwar... I think that is a terrible metaphor and I think that is a terrible concept. There are no winners in that environment."
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What I want to know is, does any department of the United States government have a definition for cyber-warfare that members of that department consider to be 'official'?

Answer: 
There [seems to be no formal definition](https://fas.org/sgp/crs/natsec/R43955.pdf) (as of 2015):

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> Although there is no clear doctrinal definition of “cyberwarfare,” it is typically conceptualized as state-on-state action equivalent to an armed attack or use of force in cyberspace that may trigger a military response with a proportional kinetic use of force. 
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[US Legal](https://definitions.uslegal.com/c/cyber-warfare/) gives this definition:

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> Cyber warfare refers to a massively coordinated digital assault on a government by another, or by large groups of citizens. It is the action by a nation-state to penetrate another nation's computers or networks for the purposes of causing damage or disruption. The term cyber warfare may also be used to describe attacks between corporations, from terrorist organizations, or simply attacks by individuals called hackers, who are perceived as being warlike in their intent.
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However, it is unclear whether this is an official definition used by the US government or is something they defined themselves, as it doesn't cite any US codes.
[United States Cyber Command](https://en.wikipedia.org/wiki/United_States_Cyber_Command) (USCYBERCOM) handles cyberspace concerns for the Department of Defense, and seem the best source of any sort of definition for 'cyberwarfare' or 'cyberwar'. Overall, they don't appear to reference 'cyberwarfare' as it's own domain, rather they refer to cyber operations as another integral part of both domestic defense and conflict abroad.

According to [USCYBERCOM's Mission and Vision](https://www.cybercom.mil/About/Mission-and-Vision/) page:

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> **The Command has three main focus areas: Defending the DoDIN, providing support to combatant commanders for execution of their missions around the world, and strengthening our nation's ability to withstand and respond to cyber attack.**
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> The Command unifies the direction of cyberspace operations, strengthens DoD cyberspace capabilities, and integrates and bolsters DoD's cyber expertise. **USCYBERCOM improves DoD's capabilities to operate resilient, reliable information and communication networks, counter cyberspace threats, and assure access to cyberspace**. USCYBERCOM is designing the cyber force structure, training requirements and certification standards that will enable the Services to build the cyber force required to execute our assigned missions. The command also works closely with interagency and international partners in executing these critical missions.
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