An alien invasion (see video above) is incredibly unlikely due to motivation factors. I discuss this and maybe what is really going on.
Recent film-makers have to deal with the anxiety in strategic thinking created by the long campaigns in Iraq and Afghanistan, and the realization that the fog of war is unlikely to be removed anytime soon.
A scene in Skyline can be read along these lines: a B-2 stealth bomber, accompanied by several drones and fighters, is able to launch a nuclear missile at the alien mothership. But it doesn’t work! The mothership reassembles and attacks again, like if nothing had happened! The scene is the anti-Independence Day moment of the movie: when the heroes realize that their most advanced technologies won’t save them and that what had been considered the ultimate weapon, able to sanctuarize a territory (see the French nuclear doctrine), is worthless.
Unsurprisingly, the new heroes are the grunts: those who hold their grounds and fight protracted battles. For example, Battle: Los Angeles is all about a platoon of Marines, led by a staff sergeant, who pretty much behaves as a strategic corporal. The marines fight an enemy literally buried under the ground, controlling the city and having established air superiority (once again, the USAF doesn’t look good). In a sense, Cowboys and Aliens can be seen along similar lines, the heroes breaching the mothership and forcing the aliens into a ground battle, hence removing their technological advantage. Can’t you smell the Counter-Insurgency (COIN) debates behind this representation of the armed forces?
Battleship is interesting on that regard because well, you know, the U.S. navy saves the world and stuff. It is probably already the sign of the end of the COIN era and the beginning of a new focus on the global commons and the strategic roles of the navies.
Causes of war. In almost all of these movies, the aliens come to grab earth’s natural resources. The want water in Battle: Los Angeles and Battleship, conducive metals in The Darkest Hour, brains in Skyline, gold in Cowboys and Aliens, or simply a new planet (ours) in the Transformers franchise. In every case, a resource-hungry alien power tries to overcome mankind in order to achieve its goals. Of course, this plot resonates with contemporary debates on energy scarcity and the need for a new global energy order.