SabreMuch as people don't like it Iran is apparently doing...

Sabre

Much as people don't like it Iran is apparently doing nothing illegal in developing nuclear technology for peaceful purposes. The challenge the US puts out to prove a negative, ie that they are not producing for aggressive purposes, is an impossible task - as it was for Iraq who had no weapons of mass destruction yet were told to prove it.

Equally it seems that the law allows for transfer of nuclear technology/knowledge between signatories to Nonproliferation Treaty. I don't know if Sudan are signatories but there would be precious little to justify the USA taking military action. That doesn't mean they won't do it of course but they would pay a big price for doing so - probably do big for them to handle.