Editing Alien invasion (section)

==Variations==
===Alien infiltration===
This is a familiar variation on the alien invasion theme. In the infiltration scenario, the invaders will typically take human form and can move freely throughout human society, even to the point of taking control of command positions. The purpose of this may either be to take over the entire world through infiltration (''[[Invasion of the Body Snatchers]]''), or as advanced scouts meant to "soften up" Earth in preparation for a full-scale invasion by the aliens' conventional military (''[[First Wave (TV series)|First Wave]]''). This type of invasion represented common fears of the American public during the [[Cold War]], particularly the [[Red Scare|fear of infiltration by communist agents]].<ref>{{cite book |last=Peter |first=Lev |url=https://books.google.com/books?id=TEGl2Ele_XoC&pg=PA177 |title=Transforming the screen, 1950-1959 |date=2006-11-06 |publisher=[[University of California Press]] |isbn=0-520-24966-6 |series=History of the American cinema |volume=7 |page=177 |quote=Invasion films were common in the 1950s featuring a variety of aliens portrayed as superior to earthlings both in intelligence and technology. In these films, aliens represent what some Americans feared about the Soviets. Invaders, friends or enemies, and often with the help of robots, either come to warn earthlings or destroy them with superior technology. Sometimes, the invaders use the strategy of infiltration, taking over the minds of the people, making slaves of them or appropriating their bodies, thus making war unnecessary. In some instances, the aliens already had a similar appearance - in ''Star Trek'', while officially made contact with Humanity in 2063, (and were not "invaders" - some were shipwreck survivors, others time-travelers, accompanied by at least one Human, from a future where their respective worlds were allies) no fewer than six Vulcans had spent some time on Earth, passing as Human simply by using hair or skullcaps to conceal their pointed ears.}}</ref> The [[Reptilian conspiracy theory]] claims that covert alien infiltration is already happening.

===Beneficial alien invasion===
[[File:Amazing science fiction stories 195810.jpg|thumb|upright|In [[Henry Slesar]]'s 1958 story ''The Delegate from Venus'', an alien robot cautions that Earth will be destroyed if its people do not learn to live in peace.]]
This theme has also been explored in fiction on the rare occasion. With this type of story, the invaders, in a kind of [[The White Man's Burden|little grey/green man's burden]], colonize the planet in an effort to [[cultural imperialism|spread their culture]] and "civilize" the indigenous "barbaric" inhabitants or secretly watch and aid earthlings saving them from themselves. The former theme shares many traits with hostile occupation fiction, but the invaders tend to view the occupied peoples as students or equals rather than subjects and slaves. The latter theme of secret watcher is a paternalistic/maternalistic theme. In this fiction, the aliens intervene in human affairs to prevent them from destroying themselves, such as [[Klaatu (The Day the Earth Stood Still)|Klaatu]] and [[Gort (The Day the Earth Stood Still)|Gort]] in ''[[The Day the Earth Stood Still]]'' warning the leaders of Earth to abandon their warlike ways and join other space-faring civilizations else that they will destroy themselves or be destroyed by their interstellar union. Other examples of a beneficial alien invasion are [[Gene Roddenberry]]'s movie ''[[The Questor Tapes]]'' (1974) and his ''[[Star Trek: The Original Series|Star Trek]]'' episode "[[Assignment: Earth]]" (1968); [[Arthur C. Clarke]]'s ''[[Childhood's End]]'',<ref>{{cite book |last=Parrinder |first=Patrick |chapter-url=https://books.google.com/books?id=DIWoqcXGabYC&pg=PA143 |title=Learning from Other Worlds: Estrangement, Cognition, and the Politics of Science Fiction |date=2001 |publisher=[[Duke University Press]] |isbn=0-8223-2773-2 |page=143 |chapter=Estranged Invaders: The War of the Worlds}}</ref> the novel (later anime) series ''[[Crest of the Stars]]'', the film ''[[Arrival (film)|Arrival]]'' (2016), and [[David Brin]]'s [[Uplift Universe]] series of books.

=== Invasion by humans ===
[[File:Alien invasion.jpg|thumb|Illustration of how alien invasions are often depicted in contemporary popular culture such as modern science fiction films]]
A similar trope depicts humans in the role of the "alien" invaders, where humans are the ones invading or attacking extraterrestrial lifeforms. Examples include the short story ''Sentry'' (1954) (in which the "aliens" described are, at the end, explained to be humans), the video game ''[[Phantasy Star II]]'' (1989),<ref name="gspot_phanstar2">{{cite web |last=Kasavin |first=Greg |date=July 15, 2005 |title=The Greatest Games of All Time: Phantasy Star II |url=http://www.gamespot.com/articles/the-greatest-games-of-all-time-phantasy-star-ii/1100-6129293/ |access-date=2010-09-13 |website=[[GameSpot]]}}</ref> ''[[The Martian Chronicles]]'' by [[Ray Bradbury]], the Imperium of Man in the ''[[Warhammer 40,000]]'' universe, ''Invaders from Earth'' by [[Robert Silverberg]], ''[[Ender's Game]]'' by [[Orson Scott Card]], and the movies ''[[Battle for Terra]]'' (2007), ''[[Planet 51]]'' (2009), and ''[[Avatar (2009 film)|Avatar]]'' (2009).