This entirely new shiny edition of Tomorrow's War is now a game on its own, and is no more considered an expansion of the Force on Force basic rules. It is also the first one to be actually printed,
A previous sort of "beta" edition was just sold as a .pdf and as an expansion for the Force on Force basic game. Extended playtesting and feedback has permitted the developing of a stand-alone game.
From the Introduction in the book:
Tomorrow’s War is a science fiction military miniature wargame with emphasis on "hard" science fiction rather than "Space Opera" or "Science Fantasy." This rule book contains background material for gaming in Ambush Alley's campaign setting, but the rules themselves are not background dependent. You can use them to game gritty science fiction engagements against whatever narrative backdrop you choose.
Tomorrow’s War can be played with figures of any scale.