Stuxnet: who is doing this?

First of all, I don't think it is the U.S. or Europe. However, if it is a nation the nations most likely would be: China to demonstrate that it can and to tell Iran that it shouldn't destablize the world anymore than it already has by creating nuclear weapons. Saudi Arabia because they feel threatened by nuclear weapons in Iran more  than by Israel. Because at least Israel has demonstrated logic and rationality about weapons in general. India, because India considers both Pakistan and Iran a threat to its ongoing stability. Or Israel because it can and thinks that doing this is more efficient than losing any soldiers.

However, if it is any nation state creating Stuxnet, they likely hired a corporation or the best hackers on earth to do this. The problem with this kind of worm is mostly that it will lead to even more efficient worms.

The problem with this is that with more sophisticated worms than stuxnet is that it could have the effect within any nation state of an electromagnetic pulse or EMP that could be generated from a 100 megaton nuclear weapon 100 miles up. In other words, all the factory equipment or electrical generating stations could be made to destroy their equipment through electrical overload, functioning at the wrong speed or calibration etc. and thereby destroy or at least shut down necessary equipment for keeping an electrical grid within any nation functioning.

So, I see the problem with this kind of worm is the same problem with an Armed Drone anywhere. They both can be potentially seriously misused in seconds and both cause untold damage that could make 9-11 look like a cakewalk. And either the worm or the armed drone could do this in an instant before anyone understood anything. And the reaction of nations to this could be catastrophic until the truth was known which might be weeks, months, years or never. Here are some word buttons to articles and videos on the subject.

Who's Behind Stuxnet? The Americans? The Israelis?
Stuxnet worm hits Iranian nuclear plant

Stuxnet - Wikipedia, the free encyclopedia

Videos for stuxnet

Cyber Worm Targets Power Plants, Factories

Falkenrath Says Stuxnet Virus May Have Origin ...

 The main reason I don't think this is the U.S. doing this is that they have much more to lose in doing this than anyone else. By hosting the United Nations in New York, the United States has to appear to be a more neutral arbiter for the world. This kind of Stuxnet action is not the kind of thing the U.S. would likely get involved in at any time (unless it was in self defense).

So, from this point of view of self-defense if that is the only criteria then Israel is the most likely nation to have done this if I only consider self defense. However, it could be done by someone or some nation trying to start something between Israel and Iran. This is the real problem with the whole thing that I see at present.