One thing I’ve come to notice in SF from many different eras and subgenera is the theme of war and conflict. Seemingly transcending all else, themes of violence on a grand scale find there way into many different types of SF from short stories and novels to movies and television.

One reason this is the case is due to the immense technological progression surrounding wars. Powered flight, for example, was first achieved in late 1903. By 1939 both the first pressurized aircraft and first jet aircraft were zipping through the skies. Less than ten years later, the sound barrier was broken. In the brief span of 63 years humanity went from two bicycle engineers at Kitty Hawk to standing the surface of the moon, and what defined those 63 years was largely war. WWI , WWII, and the Cold War progressed technology so rapidly that many of the things we take for granted today are byproducts of combat. This rapid progression inspired generations of SF writers, in particular the creation of the atom bomb. Such developments as these lead authors to wonder how the technology of the future might change wars, and what sort of wars will be fought.

The nature of wars depicted in SF are also of note. For example, in a space-faring world in most cases fighting over land on earth doesn’t make a great deal of sense. Authors imagined alien invasions, inter-galactic conflicts, and more to show what type of conflicts may arise in the future. Humans fighting each other, or humanity banded together against some larger external threat.

The nature of future wars has long been considered by SF writers and future-thinking people. Thomas Edison once said that the only “way to make war impossible is for the nations to go on experimenting, and to keep up to date with their inventions, so that war will be unthinkable, and therefore impossible.” (this is quoted from https://www.depauw.edu/sfs/backissues/64/gray.htm , where the specific citation can be found)