Yes, as citizens of the United States they will be subject to U.S. Laws. However if some extrodinary event occurs, I'm sure the U.S. will defer to diplomacy. Also, needless to say, the children will always be special and have certain, shall we say, favors bestowed upon them because of their very special heritage. It's a shame they can't/won't/don't want to live in France where I believe they should be honored.