Tweet of the Day: Layers of Reality
Let us, once again, quote from the trope page:
The planetary cousin to the Standard Sci-Fi Fleet. While the Space Navy dominates the sky, it’s up to the ground pounders to take the ground. It is sometimes claimed that the use of militarized spaceships will make planetary forces obsolete. After all, why waste men and vehicles on the ground if you can just blast them from orbit with lasers, missiles, plasma bombs, or huge rocks? The answer is simple: Because unless you’re going for genocide, you will need to be able to hold your new territory after you’ve blasted the defenders to ashes. If nothing else the invader needs a base to build supplies for his next glorious conquest. And of course he will want some subjects from which to collect the oppressive taxes needed to pay for his mighty fleet. Not to mention mopping up enemies not concentrated enough to warrant turning starship-grade weaponry on, pacifying local populations, and probably defending ground infrastructure or even taking targets that are too close to places you don’t want blown up, or that are somehow protected against orbital attacks. (This is also the reason modern countries still have armies in the face of modern air power).
The real reason for any story to have an army of sorts is Rule of Drama.
The hero of a space navy is The Captain, the hero of an army is the Grunt.
Ship to ship combat maybe dynamic, but it is also technical, all about missiles, lasers and deflector shields.
Ground combat is about smoke, sweat and tears. Groveling in the mud, stalked (or stalking) a sniper, pressing down on a bloody wound while yelling, “MEDIC!” It may be about glorious death in combat, about the coward that finds his courage, about sneaking in into an enemy fortress or the slow drag of muddy trench warfare. Even doctors get their chance to push their hands into a patients guts and work against the clock to save a nineteen year old only to see him ship back to the front lines. He may even do it while dodging bullets himself.
More often than not a sci-fi story will focus on infantry, be they special forces, in power armor (as to double as tanks) or with a rifle and a prayer. He (although women are often portrayed since modern tech makes everybody equal on the battlefield) is often a space marine, since job #1 in any sci-fi setting is to go down to the planet and take it. It fits well with many a WW2 trope born out of the Pacific campaign. While fancy ships slug it out in orbit, it is the humble marine who has to take and hold whatever rock the brass wants to park themselves on. Marines also have the reputation of being elite infantry, since their job requires a mixture of very specific training, stamina (both mental and physical) and tactical flexibility under fire.
The can do attitude and thirst for combat doesn’t hurt either.
And to heap on the Rule of Drama, when it comes to modern wars (and their future counterparts) a strange mixture of weapon lethality and life saving medicine can lead a poor S.O.B. surviving a the shell that caved his skull in but having his mother wipe the drool of his mouth until the day she dies thus reducing life to a technicality.
Don’t expect to see that much in video games or TV/Movies, but military sci-fi writers are not that squeamish.