why did you bring up the 'society' topic in the first place?

A society leads to a structure with advantages of power and intelligence over individuals. It means that we'll always be able to restrain agents in test harnesses, for instance. It means that the designers will be smarter than the designed - via collective intelligence. If the the designers are smarter than the designed, maybe they'll be able to stop them from wireheading themselves.

If wireheading is plausible, then it's equally plausible given an alien-fearing government, since wireheading the human race needn't get in the way of putting a smart AI in charge of neutralizing potential alien threats.

What I was talking about was "the possibility of a totalitarian world government wireheading itself". The government wireheading itself isn't really the same as humans wireheading. However, probably any wireheading increases the chances of being wiped out by less-stupid aliens. Optimizing for happiness and optimizing for survival aren't really the same thing. As Grove said, only the paranoid survive.