In a little over a century, mankind had thrown itself through the shitter. While electronics have remained nearly as powerful as it had in the 2010's, society had changed. Scientists had played with genetics, leaving many more combinations of traits, and intelligent species. Warfare, however, is a constant threat, providing an unique need for local militia's. Weapons haven't gotten any more advanced, and tanks aren't very common.
Now, the world of Equestria and Earth have melded together, quite literally. This is a totally new planet now, twice as large as either worlds were on their own, and confusing as all hell. Equestria has to make a mad dash to catch up with the world around them, while the rest of the world fights over the new source of resources, except for one, which has to do it's best to keep their new neighbors from being exterminated.