From Strategy Page:
November 6, 2008: Cyber Wars are already underway, but the practitioners are doing it covertly, lest there is a conventional counterattack. Nuclear weapons have kept the major nations from going to war with each other for the past half century. That will probably continue. But Cyber War provides an opportunity to fight an anonymous war against another nation, without leading to physical violence on a large scale. But only if your don't make the target nation really, really mad. This is a delicate balancing act.
This has been done in the past, largely by quietly supporting opposition or terrorist groups in enemy nations. The key here is hiding your tracks. The earliest signs of this was the highly damaging Code Red virus of 2001, which apparently came from China. The origin of the virus was traced back to China, but China denied any responsibility and got away with it.
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