The law might not cover it, but prosecutors can always try to convict you for it, and it's up to you to fight it in court if you feel that US law should not have jurisdiction over $Something in $Elsewhere.
I doubt most US courts are likely to say, "well we don't have jurisdiction over __that__".
Right; Richard O'Dwyer is actually an example of exactly that (the US didn't even win in the end: the situation dragged out and was settled and the charges were dropped; they sadly, thereby, also did not clearly lose).
I doubt most US courts are likely to say, "well we don't have jurisdiction over __that__".