Using a shared metaphor…the “Prime Directive” became a science fiction trope because of our own history. Yes, everyone forgets aliens are alien; human history and sociology will be inadequate guides to first contact with aliens. They are, however, good guides to first contacts between humans.

First, there is the danger of our very common diseases, which we know can be deadly to isolated populations. Then there is a great deal of historical and current evidence that so called ‘primitive’ human cultures can suffer greatly when contacted by more complex ‘advanced’ cultures. (There are aspects of American culture that are corrosive to more traditional cultures. Heck, there are even groups of people in this country who pretend it is still 1950, or even 1850 in order to deal with daily life).

And don’t forget, they know we’re watching. Our giant angry birds have already flown over them many times. So, I don’t think we can “protect” them forever; eventually, something will happen to accidentally, yet truly, reveal the outside world to these tribes. But, I do think a great deal of care, and study, should occur before actual contact.