59

Assuming that the object is to protect earth, and not just hide away when the aliens come... Join the Department of Extraterrestrial Defense The Department was founded in the sixties, at the same time as the project to create a psychic supersoldier using LSD. Currently it consists of one insane bearded guy, in the 22nd basement level of the Pentagon. ...


44

There are a couple good answers already about how Paul can help the world prepare by sharing knowledge, or advancing technology. But if he is really prepared to consider any option, to take any action, there are at least a couple more options he should consider, whether or not he actually decides on using them. Take up Super-villainy Honestly, there is ...


43

Annexation can be defensive in nature. Alien race A may know of an impending invasion from alien race B, and are attempting to annex Earth to protect it. Alien race B is out to conquer new worlds but knows that if it attacks part of alien race A's empire, a large-scale war would break out and race B would suffer greatly. Annexation by race A would serve ...


39

why invade at all? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. But you might not want to blast them from orbit because these items might also be of value to you. You might want to avoid ...


28

Keep in mind that an alien civilization might have a concept of ethics and morals which is completely different from ours and completely incomprehensible from our perspective. They might have evolved into a centralized, non-violent hierarchy millennia before they even developed technology. A decentralized system with independent countries and organization ...


27

This has been done many times. The European colonisation efforts in India, Africa and Polynesia amongst others are very well documented, but many outfits did the same. Basically you provide weapons and perhaps training and expertise to one side to defeat the other in their own interests. Then pick a reason to wipe out the first. Or just arm the remnants of ...


23

Sir, here is your Prime Commander with an extensive report on our position. We are not reciving support The empire has, once again, refused to send more soldier to help us, saying that for those puny humans our flotilla should be more than enough and, as commander @Zhehao pointed out, FTL is too expensive anyway. We are on our own. High power weaponry I'm ...


23

Don’t drop one asteroid. Drop thousands The mathematics of impacts is fairly well understood (though it is a little fuzzy at high speeds). For any given weight and shape of ‘asteroid’ (really an aerodynamically shaped, ceramic coated lump of rock with some engines attached) hitting the ground at any given speed: You can quite accurately predict the blast ...


20

Invent it. Big changes have taken place in the US, I gather. If there are thousands of superintelligent AIs milling about to be conscripted, over previous years there were probably other issues involving AIs and semisentitent automatons. You can invent your government agency to deal with these. Heck, The Department of Motherland Security was only ...


19

Stealing a little from @DJClayworth's answer, this answer is probably too self-insert-fan-fiction-y to make a good story, but it is exactly what I would do: Tell Carl Sagan On September 28, 1980, PBS aired the first episode of Carl Sagan's Cosmos. It quickly became the most-watched American television program of all time for a decade until it was ...


18

Please note that this answer was submitted before the question was edited to include the new 'Accepted Answer' conditions. The aliens are a parasitic race The aliens land in cities all over the world and demand that everyone submit to one specific test - an anal probe. When asked why, all they will answer is - "It is necessary for the survival of ...


16

Can't beat em? Join em! Your refugees contact a selected Earth government. They ask for help. They say that they are fleeing their dead world and need a place to live. They have advanced tech they are willing to share. Plus they are xenocurious humanoid hotties who only wear skin tight silver lamé space jump suits. There is no government on Earth that ...


16

Engineer a virus specifically targeted to kill humans which is very contagious and has a long gestation time, say 6 months. Introduce it into various cities around the world and let it spread invisibly. Wait 6 months and watch the majority of the human world population vanish. Sprinkle it on the remaining patches of human settlement to finish the job.


13

Swarm and flock members follow very simple rules that let them maneuver in concert with the others. They use the perceived rate of change in speed and orientation of their most immediate neighbors. http://www.red3d.com/cwr/boids/ If the aliens adopt such a pattern of flight, it's a strong indication that they follow similar rules, with comparable inputs. ...


12

Before the Cold War began, aliens attempted their first invasion. This would have been around the end of WWII, over Germany. The aliens actually struck Berlin and shredded most of the Nazi party. The Battle of Berlin was actually the first battle against the aliens. Hitler's body was never found because the allies didn't kill him - he had already been taken ...


11

Because humans are really stupid and overestimate the importance of brain because, no surprise, it's their brain who tell them he's the important one. But there are only 100 millions neurons in brain. 5 time less than in guts. Aliens know that (that's why they are so advanced) and after doing "catch and release" they concluded they need to do mass check-...


10

Since he got such an intelect as to become an honoris causa engineer and scientist in many different fields, he can use his free time and knowledge to design novel weapons for the military and fill in applications for patents. In time he'll be noticed by companies such as Lockheed Martin or its competitors. He's bound to have a good job, which will grant ...


10

They want to understand how a bipedal species could achieve the level of intelligence we did. Source: https://www.smbc-comics.com/comic/evolution-3 The aliens are born from cloacas, and they can't understand the difference between cavities and have mistaken human asses for human birth channels.


10

Unless you're using some form of handwavium drive you have some incredibly powerful energy emitter on your starship--remember the Kzinti lesson. For your ship to have made it across the stars without being a slowboat it must be expelling something at high relativistic velocity. If it's any sort of particle simply point the drive at the planet--fry every ...


9

Most of the answers, and indeed the implications raised in your question would seem to make this a non starter. Labour? An alien race which can build starships and cross interstellar space can use energy and resources on a scale that is literally unimaginable to most modern day earthlings. It would be much like a wealthy Arab sheik deciding that he will ...


9

Why kill useful workers? Humans are herd animals, it is relatively easy to keep them inline. Especially if most are unaware that they are being kept inline. The easiest approach would be to gain trade access, followed up by enlarging their own population while simultaneously causing attrition to the indigenous population. The last step would be complete ...


8

Excerpt from Skynews.au News Article: New, delicious species of desert dwelling dodo-bird discovered in Australia. Hrimfaxi Official Operational Report on Sol-III, Stardate 12345.6667 Mission Accomplished! The entire world is ours: Our campaign to rip out the hearts and minds of the inhabitants of Sol-III has been an unmitigated success. Only a few ...


8

My current idea A combination of expensive FTL travel and alien bureaucracy. I am thrown into the solar system with the bare basic tools to establish a base of operations and a few samples of embryos to get my clone army started, and even sending this much stuff at faster-than-light speeds across interstellar distances is enough to bankrupt several planets....


8

It's a large scale health study Every few years there's another breakthrough in what your gut bacteria say about your health. These aliens have taken this down to a fine art apart from one particular aspect, how to gather and identify the owner of the bacteria in question. This particular aspect they're still doing the old fashioned way. Somebody once said ...


8

The first people on the scene will almost certainly be law enforcement of some kind. Accordingly, the people who are sent in will depend on the laws they think the science team has broken. The act of setting up a new, company-owned city in the middle of nowhere, as opposed to establishing oneself in an existing city (which would be, by all accounts, far ...


8

Pushing asteroids isn't a terrible idea. They've already travelled hundreds of years, so coordinating a cluster of small asteroids to take out all the major cities of the planet in one bombardment wouldn't take much resources, there wouldn't be much we could do about it, and what's another 10 years to wait. The collapse of human society that would surely ...


8

They don't need to. Simply put, a civilization capable of traveling vast, interstellar distances to colonize another world already has the technology sufficient to sustain themselves without needing to colonize another world, much less commit xenocide in order to do so.


8

Apply directed thermal changes to key areas of the ocean. We already know that climate change can have an impact on global food sources through changing the way food is distributed throughout the oceans, and the impact that has on land dwellers. In point of fact, this isn't so hard to disrupt because most of the world's food supply is reliant on the Global ...


7

Well, I don't know if this counts as a proper answer, but to give you an idea: What would happen if I, the great siege commander, would happen to succeed in taking the earth? Would I get another unsensible assignment? Maybe even an assignment that could lead to my death even without an implant activation? Is my position in the current assignment in any way ...


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