The Peacekeepers are a private military force who can be contracted by civilized planets to keep order, although they often act autonomously as well. From birth it is decided whether a Peacekeeper is to be in the military by an enrollment officer. They are bred to be perfect soldiers and to be able to survive in a variety of hazardous environments (this does not include excessive heat or hard vacuums). They are trained to accept and obey any command given by a higher-ranking officer (in theory their military is much the same as human military). The Peacekeepers joined the Alliance of Nations.