I was just rewatching District 9 and it paints an eerily realistic prospect of how humans would treat and interact with alien species. I believe we would immediately try to quarantine them in order to find any risk of threat, biological or technological, and start figuring out where they are in regards to intelligence in relation to ours. Not necessarily even caring about their intent.
I cant imagine a scenario where any nations reaction would be positive or welcoming in any way as we would have such deeply subconscious fears of suddenly becoming prey and shattering the view we have held of ourselves.
This may cause pandemonium, in a way justifying secrets being kept regarding retrieved craft or bodies.
What do you all think? Based on the information we have, could you see a good outcome?