I might be against you guys on this thread but the concept to me is really absurd. One can't serve two masters. One can't have two wives (unless you are muslims). One can't play for two sporting teams at the same time. And one can't be loyal to two countries at once. One has to commit becoming a citizen fully, or not at all. It's really an insult to the country that the person has become a naturalized citizen of. It's a betrayal of trust.