How hard would it be to tweek that virus so it would go after American Uranium Enrichment centrifuges? The tough part of the code has already written...
As I understand the StuxNet Virus with detailed and specific information on the programming of the Iranian enrichment plant down to specific Input/Output addresses of sensors and motor controllers.
If those addresses were used at an American Plant to control critical functions with similar parameters it could cause problems. But it would have to be a Siemens PLC which dominates Europe and the Middle East. Foxborrow and others are dominate in the US.