Robert H. Gray
In 2016, Gray published an article in "Scientific American" about the Fermi paradox, which claims that if extraterrestrials existed, we would see signs of them on Earth, because they would certainly colonize the galaxy by interstellar travel. Gray argues that the Fermi paradox, named after Nobel Prize-winning physicist Enrico Fermi, does not accurately represent Fermi's views. Gray states that Fermi questioned the feasibility of interstellar travel, but did not say definitively whether or not he thought extraterrestrials exist.
The Dark Forest
Back on Earth, Luo Ji and another contemporary, Da Shi, discover that star 187J3X1 has been destroyed, causing the UN to restore Luo Ji's Wallfacer status. Luo Ji explains to Da Shi the implications he derived from Ye Wenjie's two axioms of cosmic civilization: 1. Each civilization's goal is survival, and 2. Resources are finite. Like hunters in a "dark forest", a civilization can never be certain of an alien civilization's true intentions. The extreme distance between stars creates an insurmountable "chain of suspicion" where any two civilizations cannot communicate well enough to relieve mistrust, making conflict inevitable. Therefore, it is in every civilization's best interest to preemptively strike and destroy any developing civilization before it can become a threat, but without revealing their own location, thus explaining the Fermi paradox.