There have been many cultural readings that link the connection in ideology to the real-life Spartans and fascist or militaristic organizations, and the Halo series rightfully digs into that subtext to inform its characters. Related: Halo: Who Are Spartans and How Do They Differ From the Video Games? The series truly kicks into gear when Master Chief is given a direct order to kill an innocent civilian who refuses to cooperate with a propaganda campaign, and instead of just doing what he is told makes a choice for himself based on a gut feeling that goes against years of programming and training. Just like the Spartan armies of real life, children are inscribed into being trained to be warriors, and it is an entire culture based around the glory of battle.
The Spartans are a military outfit, named after the Spartan armies, engineered and augmented to be faceless living weapons.