If aliens are really in contact with the government, I expect they would have wanted us to get our population under centralized control before they're willing to work with us.
I think they actually were going to contact the leader of the free world - the greatest country on the planet and then, well...they saw who the president was. Said screw it, let's go to Alpha Centauri.
No way. On the Death To Humanity scale, China be in front Putin's Russia. 'Merica (even the MAGA joke) be way down in 10th or 20th. But the point is that Xi is one of the smoothest mad men we've seen in a century. "Ewwwww."
They're absolutely dystopian, but in terms of a planetary scale of one world government they're model works as well. Just depends on what type of aliens we're dealing with here...
Don't give up on America. We still know how to be number one in other humanitarian endeavors. http://news.bbc.co.uk/2/shared/spl/hi/uk/06/prisons/html/nn2page1.stm
I think this is why in shows/movies like Firefly, you see Chinese/Mandarin being the dominant language of commerce/trade and the American-style cowboy being the outlier.