We know, deep down, that we may one day be on the other side of this equation, that the United States won’t be the world’s main superpower forever. Past superpowers have often only realized their new status when they suddenly faced a sudden, damaging assault from a rising power. Plus, as the main power on the receiving end of asymmetric warfare, we can’t really understand it unless we see it from the other side.
Science fiction is also uniquely suited to talking about the realities of post-Cold War fighting, because so much of asymmetric warfare deals with a technological superiority on one side. The idea of how you cope with a technological strategic advantage is one that science fiction can easily dramatize, because alien technologies are automatically going to be awesome and incomprehensible. (And on the real side, any alien race with the ability to travel interstellar distances to visit Earth is going to be massively more powerful than we are.)
First, I think we’re more likely to end up in a bi- or multi-polar world than we are in a uni-polar world where the United States is not the dominant nation. That’s where movies like District 9, but on a much larger scale, would be interesting—there’s no question that an alien invasion that humanity successfully repulsed would fundamentally reshape our society, likely making the world both more unified across national lines, and more militaristic a la an Ender’s Game scenario. But it would also likely make us cling more fiercely to our humanness in the face of its potential annihilation. Humanity in general and the U.S. in particular would probably change more if we shifted into an uneasy coexistence with an alien society where technological and cultural exchange were possible, but potentially politically taboo.
Second, while the U.S. probably will be less geopolitically powerful in the future, isn’t there an extent to which taking on the underdog role in alien movies sort of absolves us of our role as an invader? Right now, we are fighting two actual asymmetric wars, using technological strategic advantages like predator drones. A movie about a human invasion or colonization of an alien planet might be a more accurate way to process American emotions about our military superiority and the kinds of things we do with it.
And finally, one thing that’s worth mentioning is that in asymmetric wars, the smaller, less conventionally powerful party to the conflict can still find powerful ways to fight back. Whether you’re flying planes into buildings or making very effective use of Improvised Explosive Devices, asymmetric warfare often spurs strategic and technological innovation on both sides of the conflict (see the valorization of hacking in Independence Day). One of the things that’s irritating about so many alien invasion movies is how quickly they’re resolved. Do we really think a society capable of interstellar travel and planet seizure is stupid enough to get beaten up by a bunch of council housing kids in the U.K., as awesome as that scenario is? Or to invade via Los Angeles rather than taking out command centers and nuclear weapons stockpiles first? No, if humanity doesn’t just surrender immediately, this is likely to be a protracted quagmire, the kind of thing that produces actual innovation and strategic shifts. It might involve less of Will Smith punching aliens in the face, or whatever, but it would probably make for better storytelling.