If I were the leader of a major world power right now, I would push for a law in my country that decriminalizes the hacking of any government systems of countries that have proven hostile to my countries government. The only exception would be the hacking of public infrastructure like transportation systems and public utilities. Everything else would be fair game. Seems like this approach would introduce and element of M.A.D. into the mix that would mitigate the current hostile actions we are seeing from the US via the NSA and China via the PLA.