I believe that God is stopping them. The Bible implies that we are an experiment to show the outworking of sin.
There may be aliens in rebellion who are working with the Rebellious One. They will be judged as well. Or perhaps aliens are the fallen angels taking different forms.
I think many of our leaders are, knowingly and unknowingly, being involved in the cult and possibly discussing with demons, thinking they are discussing with how to bring Earth into some planetary federation and our leaders think they are doing us favours by doing so but don’t understand that they are being deceived.
What about this, there are no aliens. In fact there is not one shred of evidence that points to any other intelligent life in the entire universe. E
ven if there were other intelligent life that could communicate with us, there is little chance either civilization would ever know of the existence of the other because of the vast distances i.e., the amount of time required for our radio or laser communication technique to travel between the civilitations. Most likely our civilization and theirs would exist and then end before we ever knew the other existed.
It is also possible that earth is the first planet to spawn intelligent life, somebody has to be first, why not us. Maybe we humans are the first life in the universe that has successfully gotten past the great filters which allow for basic single cell life but create almost impassable barriers to evolve all the way to intelligent life like Humans.
For instance, the leap cells made from Prokaryote cells to Eukaryotes cells. Without that leap 2 or so Billion years ago it is doubtful that any multicelluar or animal life would have ever appeared on Earth.
Or the moon; without the moon to stabilize the earth’s rotation there never would have been the long time frames of relatively stable environmental conditions which allowed for the evolution of life into multicellular and then to intelligent animal life.
Don’t get me wrong, I suspect that basic cellular life is most likely in many places even in our own galaxy. It would seem, at least according to our single data point, Earth, and extrapolate it; Life seems to have started on earth about 4 billion years ago, almost as soon as the young earth could support life, boom it was there. So I think we as a species, as we go out and colonize other planets/asteroids etc...etc..., we’re going to find that basic single cell life is going to be abundant but I doubt we humans will ever meet intelligent life anywhere because the great filters make it nearly impossible for basic life to evolve into intelligent life.
As far as we know, life evolving from single cells all the way to intelligence at our level has only happened once, and it took about 4 billion years to do it; until there is some kind of evidence that there is intelligent life elsewhere in the universe, that’s my story and I’m sticking to it.
I don’t believe there are aliens - as in, beings from other planets.
Now, you raise an interesting point - could “aliens” be fallen angels? That’s certainly possible, or as you suggest, demons, and other principalities of the Fallen One.
But, there’s nothing I’ve read in the Bible that would indicate beings from other actual planets. YMMV, and of course, I could be wrong. Won’t know til I’m dead and in Heaven.