According to a yet-to-be-peer-reviewed paper by Alberto Caballero, a Spanish researcher, it is not a leap to believe if the aliens are anything like humans—that is, if they are war lovers and willing to invade the territory of others.
There is a very strong chance that their numbers will pose a potentially serious threat to Earthlings.
The first caveat, as Vice notes in an interview with Alberto Caballero, is that the paper's sole author is not an astrophysicist, but a conflict resolution PhD student at the University of Vigo.
However, they have demonstrated skill in the field of extraterrestrial intelligence field discovery by publishing a separate paper in the International Journal of Astrobiology about the potential origin of the infamous Wow signals!
Part thought experiment and part game theory, Caballero's admittedly out-there paper is also interesting because of the way he came to his conclusion: by using a formula that takes into account how technological developments brings civilizations together to make less likely to invade others.
Using data known about the ways humans have historically invaded each other's territories and comparing the number of estimated habitable exoplanets in our home galaxy, this alien-focused conflict resolution researcher concluded that although four hostile alien civilizations may be our galaxy, much more likely to be destroyed by an asteroid than Earth is invaded by bloodthirsty aliens.
"I did based the paper only on life as we know it," Caballero told to Vice. "We don't know anything about the brains of extraterrestrials. An extraterrestrial civilization might have brains with a different chemical composition and they might not have sympathy for us or they might have more psychotic behaviors."
There are a lot of base assumptions going into Caballero's paper: first, that even an extraterrestrial civilization would be interested enough in humanity to invade us, and second, that increased technological advances would make them less war-like and more No.
But given that space peace between the U.S. and Russia continues to boom amid the post-U.S. invasion of Ukraine, it's probably not so much of a stretch to believe that if aliens are anything like ours, they'll travel the universe. Their potential ability to do will be in their control.