The UN recently decided to appoint an ambassador in case of alien contact. Is this a good idea?

From a constructivist perspective, the United Nations appointing an ambassador for extra-terrestrial affairs is a very smart decision. Constructivists are very concerned with their identity and the images that they give others, as well as the identity and image that others have. Assuming that aliens ever come to Earth, an ambassador would be seen as very non-threatening. It would give the sense that the world was open to diplomatic negotiations and might help divert a small portion of the tension that comes with making contact. We might look at the idea of diplomacy as an institution in itself, and the norms that diplomacy has would help quell hostilities that the aliens might perceive. However, if some countries think that the ambassadorship is unnecessary, then they may not recognize the validity of the post and disregard it completely. The UN needs to cultivate the image of the alien ambassador is useful and completely necessary for security reasons, without sending the world into a panic.

From a realist perspective, the ambassador can be useful but in a much different way. A realist would argue that everyone works in their own self-interest, regardless of what any other state does, and that the work is all to achieve dominance. Thus, if aliens come to Earth, the ambassador would put on a nice show for a little while but conflict would inevitably ensue. Both aliens and humans would be fighting for dominance, so conflict would be a foregone conclusion. They would not be able to trust each other. The aliens would probably not trust the Earth ambassador in the end.