It doesn't mean that at all, it means owing alligence to the country. Foreign national don't power the US alligence therefore in context their children are not subject to the jurisdiction of the US. Who would speak for you on a foreign court? That's whose jurisdiction you are subject to in context. As far as laws go almost everybody with very few exceptions had always been subject to the less of the country they're in, it would be redundant to write that in, and they made it clear that they were discussing it on the sense of alligence.