I look for a role that hopefully I feel empathy with and that I can understand and love, but also that has that challenge for me to play - a different kind of role, a different type of character, a different time period.
If there are going to be people out there making war on other people, don't you think it's a good idea for some of those people to at least follow a code of ethics? Not 'honor' but something you can pin down and be sure of, something with the same rules for everybody.