Regardless, by Sean’s own admission criteria, TDESS is not in his list because the aliens are not “hostile from the get go.” Gort kills in retaliation for Klaatu (the Michael Rennie character) being attacked first. The aliens are not benevolent, but I think this is necessary in order to make Klaatu’s warning at the end of the movie not seem like an idle threat.

Perhaps I have a broader view of what an invasion is, Klaatu lands on Earth and threatens the human race with destruction should they not cease their own conflicts. The film illustrates the paranoia of an invasion, the people feel as though they have been invaded given the possibility of the alien being among them. It doesn’t necessarily require an all out attack on Planet Earth for there to be an “invasion”, that would be a very narrow interpretation. Gort kills two people, the aliens obviously have no qualms about killing humans should it ensure the fulfillment of their goal. Is there a certain amount of people that need to be killed for it to be an attack on the human race? As far as I’m concerned, the Planet Earth is invaded, and the only reason more people aren’t killed is because they do not hinder Klaatu and his efforts to communicate his warning/threat.