I am not sure if there is anything like a collective consciousness or not, although some experiments certainly suggest that there is. In any event, it is certain that we do not understand exactly what consciousness is, much less exactly how it works. If we accept that aliens exist, and particularly if they introduce themselves to us, we and they establish a relationship in which each is a part of the other’s world, or put another way, we will share a degree of consciousness. I am not sure that would be good for us or them, and it may be why we will never see a “Take me to your leader” event.
Lue Elizondo has spent a good amount of time alluding to consciousness when questions like "what are we dealing with here?" are raised.
Not sure where he is going with that, but it is interesting as hell.
Which leader would they or should they recognize?
United Nations?
China?
US?
Individual states?
Pentagaon?
England?
Chile?
Whomever they partner with partner with would shift the rest of the world.