The dynamics of this situation are weird. Leave them uncontacted for however long out of principle, monitor them from above, commit to preserving their culture, but then intervene and try to manufacture a truce between tribes (thereby interfering with their culture) because <i>we</i> want to keep them around.<p>"Hey guys, uh, you know, we were pretty happy to just let you do whatever, but we've been watching you for a while and you've started taking risks. We're not real fond of risks. Would you prefer not taking risks for us please? It would make us feel much better about letting you do whatever you like if you didn't take any risks."