US law does not trump Syrian law. You are still ignoring my points. Try again.
I did not say USA law trumps Syrian law, but nonetheless, the USA can try people for treason against the USA while the person is in another country, and request extradition, which we are dealing with international relationships. The problem is the extradition has to on agreement of both countries. We do not even have effective diplomatic relationships with Syria to effect extradition, though Syria may consent to extradition, or the person may voluntarily come to the USA for trial which may be the case here.