I think that it's hard to make the case for open warfare when you can't prove that it was the (for example) the Chinese government that launched the attack. Or are you suggesting a covert retaliatory attack?
Open war, covert actions, or economic sanctions would work fine on a state v state level.
In the case of non state actors, current policing methods should be sufficient. In the cases where its not (and there is sufficient cause) covert policing actions should not be ruled out.
Any act of electronic warfare has an equivalent physical response. Regulation such as this is nothing more than power grabs by government and the defense industry.