I've lately been looking at a lot of War of the Worlds remakes/spinoffs, like the 2005 film, the 2013 mockumentary The Great Martian War, and of course, the tabletop game All Quiet on the Martian Front. While looking through all these awesome stories and scenarios, one question has been bugging me for a while.
Why exactly ARE the Martians invading?
(This is not a question about the novel/movies/etc. It's a question about Martian invasions such as the one depicted in this story. Why would they do that?)
Before I get into my qualms, lemme present you with some research I've done. The original story was initially written in the late 1800's-early 1900's, by the brilliant H. G. Wells himself, as a commentary(?) on the imperialistic mindset of certain countries at the time. In the year 1913 (which is roughly when the story could take place), the world was on the verge of war. Europe was growing more divided as Britain allied with France and Russia, and Germany partnered with Italy and Austria-Hungary. An arms race had begun, increasing European military spending by 50%, and the Ottoman Empire was fracturing more and more. All it needed was that one little push to send everyone biting and kicking each other.
Now back to War of the Worlds.
In all the sources I'm finding, the reasons for the invasion don't pan out, or at least seem pretty dumb. Several play with the idea that the Martians are harvesting humans for food. However, as we all know, they die off from Earthly diseases, so collecting humans which are full of Earthly germs would be kinda dumb; after all, who knows if humans are safe to eat if they live on another planet? Obviously, this sounds more like a paranoid xenophobic fear than a realistic cause for War.
The mockumentary (spoiler alert) played with the idea that the Martians wanted to collect the metal and resources humans had put into their military, and used the war as a means to collect. But there are plenty of better sources of metal in the solar system. Heck, the asteroid belt's right there, open for harvesting, and it won't try and shoot you back. So no dice there either.
And as for the Martians being afraid of human destructiveness, keep in mind that this was the early 1900's. The first atomic bombs wouldn't be tested for another 20-30 years, and airplanes weren't even a thing until just a couple years ago. So what would a couple million humans do to Martians which already had HEAT RAYS AND INTERPLANETARY TRAVEL down pat?
So I now ask you...what WERE the Martians thinking? Empires only expand because of good reasons, whether food, resources, the completionist tendency to fill in all the empty spaces in a coloring book, or something.
What would prompt aliens from a desert world like Mars to send a dozen or so War machines on what would likely be a one-way trip to another world - a world with a radically different biosphere and gravity, mind you - and then start attacking the native population?