Unfortunately, GDI has yet to release any information beyond what has been acquired by commanders in the field about the Zone Defenders. It is currently unknown given the considerable presence of the Defenders within GDI ranks. All that is deduced is that they were spun as a cross between the Zone Trooper (or Zone Raiders) and GDI's history of missile-wielding infantry, such as the Missile Squad. Otherwise, there is no indication of the history or these GDI infantry.