Think of how outraged we'd be if Iran responded to Stuxnet by attacking the U.S. or Israel militarily. In general, hacking (aka "cyberwarfare") poses an intell

Think of how outraged we'd be if Iran responded to Stuxnet by attacking the U.S. or Israel militarily. In general, hacking (aka "cyberwarfare") poses an intelligence challenge to determine whether an attacker is affiliated with or acting on behalf of a state. If United States infrastructure were attacked by a group of highly skilled individuals inside Iran or China, like you suggested, who had no apparent government connections, it would be very hard to determine whether they had been surreptitiously aided or manipulated by a government intelligence agency, perhaps by anonymously sharing technical information to aid their attack or by infiltrating the group with an agent who pushed them to action and steered them toward particular targets.