We should demand that the U.S. behave in an ethical fashion, but I'm not sure what is supposed to be unethical about Stuxnet or Flame. The Iranians have secretly launched a program that will allow them to enrich uranium to weapons grade. Since Iran is swimming in oil and natural gas, this is a pretty clear signal that the regime wants to build a nuclear bomb, or at the very least, they want that option on the table. Rather than bomb the facility, and putting American pilots and Iranian civilians at risk, the U.S. and the Israelis blew up their centrifuges with a virus. That's a hell of a lot more humane than dropping bunker-busters from a B-2. As for Flame, it spies on people... and yeah, espionage is sort of a dirty business, but it's always been that way, long before the internet. I don't see how spying digitally makes it any more unethical than planting a bug in their office. There are weapons that are by their nature unethical- nuclear, chemical, and biological weapons, which are indiscriminant and cause a lot of suffering. But cyberwarfare isn't like that, it's capable of being extremely targeted and can neutralize a target without any loss of life or suffering.
Richard Clarke writes about this in his book Cyber War, and it's actually a pretty insightful take on the situation. His argument is that there's no point in some kind of blanket treaty against cyberwarfare. But, he argues, it makes sense to have policy and treaties that prohibit certain kinds of cyberwarfare. He argued that the banking system should be off limits. Civilian targets should be off limits. Attacking power grids and other infrastructure should be off limits, unless you'd already entered into a shooting war. So far, the U.S. appears to have restrained from these sort of attacks. You can't really say the same thing about certain other countries. North Korea has been involved in attacks against banks; Russia has attacked civilian sites, and China has supposedly spent years planting logic bombs that would allow them to turn off the lights in the U.S.
I think this view makes a lot of sense. Talking about banning cyberwarfare is sort of like looking at the Wright Brother's plane and saying that we should ban the use in aircraft in war because civilians might be targeted. First off, it's a legitimate tool of war. Second of all, it's gives you a tremendous military advantage, so it's going to happen, the only question is how. As a good rule of thumb, I think you could argue that if you'd be justified in dropping a bomb on a target, you're certainly justified in taking it out with a piece of code. Likewise, if it's not okay to bomb it, it's not okay to take it out with a logic bomb.