This is just a short, easy-to-read paper I keep in my bookmarks and go back to occasionally. It explores, qualitatively, the various outcomes that contact with alien intelligence might have. I think it's a really cool 25-page exploration of possibilities that are fun to think about. Some choice quotes:
ETI (extraterrestrial intelligence) might attack us not out of selfishness but instead out of a universalist desire to make the galaxy a better place.
perhaps ETI make contact with Earth to welcome us into the Galactic Club but only after we complete a set of required bureaucratic tasks
They may be interested in incorporating us into their civilization so they can sell us their products, keep us as pets, or have us mine raw materials for them.
if ETI place intrinsic value on lives, then perhaps they could bring about more lives by destroying us and using our resources more efficiently for other lives
My favourite section is the "unintentional harm" outcomes, which suggests the possibility that they just might squish us by accident.
One non-biological physical hazard that we could face from direct contact with ETI is unintentional mechanical harm. For example, ETI might accidentally crush us while attempting an unrelated maneuver.
Can't for the life of me find where I first heard of this, but I just wanted to share it for being fun and fairly silly yet still officially worked on by NASA.
I guess an immediate thought of mine would be immediately being afraid that the capitalist power start a new arms race for the tech they get out of that situation. It might have a similar impact on geopolitics that the discovery and proliferation of nuclear weapons had over 80 years ago.
I have to agree that the nature of the intelligence will matter. Such an intelligence could have gone down a different development path according to the material conditions it lived in and not arrived at communism at the end. That could be a possibility despite all of us here wishing for the former outcome.