Let's create a scenario for one moment: imagine we're being visited by a highly advanced civilization. Who they are, where they come from or why they're here is

Let's create a scenario for one moment: imagine we're being visited by a highly advanced civilization. Who they are, where they come from or why they're here is totally unknown. Again, just an imaginary scenario. Now, put yourself in the shoes of public authorities all over the world. Can you really schedule a public speech in front of your population to declare that someone is flying in highly advanced crafts since decades and you still don't know who or what you're dealing with? Of course not. First, you'll pretend there's no such thing. Then, you'll have the air force declare they're studying the thing. And finaly, decades after, you'll say it's possible we're being visited and that this issue must be addressed by world leaders.