Let's step back and realize that there will always be moral obligations to a society for it's members.
Darkproton,
Could you expound on the statement above? I am curious as to your exact meaning. The way you've worded it leaves me with the following question: Exactly 'where' is the moral obligation placed?....if it's 'to' a society...and 'for' it's members.
FWIW - Society's with mixed philosophies will have mixed ethics...and therefore conflicts within questions of ethics.