It’s a symbiotic relationship at times. Eg Computers became a thing, fiction ran with it and made up hand held tablet computers, Tricorders, universal translators etc, which materially (not always exclusively) influence future technology designs and directions. Today we have real tablet computers, universal translators etc which were inspired by fiction.

Edit: I missed the specific point being made that the Vietnam War was well, well before the GI Joe movies in question. Apologies!