Here are some rules of thumb for Strategic Cyber Warning that were extracted form a paper prepared by the Smarter Alliance Initiative which is a partnership between the Atlantic Council and IBM. The key points are:
- Strategic disruptive effects are incredibly difficult, far harder than are usually thought.
- No known attacks have been both widespread and persistent enough to have a significant prolonged international impact.
- Cyber adversaries are people not ones and zeros traveling down a wire.
- Adversaries with the capability to cause a strategic effect are not individuals but organizations, linked to nation states.
- Adversaries with the intent to conduct a strategic attack usually lack the capability, while those with the capability lack the intent.
- Nations have never launched a major disruptive or destructive attack against another nation unless during a period of significant tensions.
- Physical conflict begets cyber conflict.
Read Atlantic Council's issue brief here - http://www.acus.org/files/publication_pdfs/403/NATO%20Cyber%20Warning%202012.pdf