This is not exactly your focus, but this means that it can be possible for there to be a set of laws in U, such that an action is required and illegal if not present, but that this same action is illegal in C...
I.e., the predication is both meaningless and pointless, unless the supposition is that the laws of U don't hold - if C extradites a citizen of U over said action, is then U's law not supreme?
This is not exactly your focus, but this means that it can be possible for there to be a set of laws in U, such that an action is required and illegal if not present, but that this same action is illegal in C...
I.e., the predication is both meaningless and pointless, unless the supposition is that the laws of U don't hold - if C extradites a citizen of U over said action, is then U's law not supreme?