Russian developer KDV Games' last game, Perimeter, was as an oblique a take on the real-time strategy game (while still clearly being one) as you can possibly imagine. But its sales didn't match the rave reviews it received. Maelstrom is essentially KDV turning away from the frontier it reached to build upon its new-found land.
The story's been constructed by professional writer James Swallow who, among other things, has also penned episodes for Star Trek: Voyager. But don't hold that against him. Anyway, in a world of strife, a divided planet decided not to bother spending the money required to destroy an interstellar object since it'd "probably" miss.
Of course it strikes with enormous force, causing massive climatic upheaval. Cue the end of the current order in the following decades, climaxing in the tired remains of governments pressing the red button in 2042. This final upheaval is known as the Maelstrom, which is handy as it gives the game its cool name.
So in this broken world there's room for three distinct factions. The first of these is the Remnants, who are the subject of the first of the game's four campaigns. They're clearly the ones who've been constructed as the easy entry point into Maelstrom, bearing most similarities to a "standard" RTS side.
Imagine the US army with about ten years' more technical progression but who have been retired and covered in mothballs for four decades before being dug out and put to use again. That's the Remnants.