By the summer of AC 195, OZ was in full control of the Earth Sphere. However, as OZ hunted down the last holdouts of the UESA, a schism began to emerge between the Romefeller Foundation leadership and the OZ leader, Treize Khushrenad, over the emergence of automated mobile suits known as mobile dolls. The Romefeller Foundation saw the mobile doll technology as a way to prevent unnecessary casualties in battle, especially with unskilled pilots. Treize was adamantly opposed to mobile dolls because he believed that without the human element, there would be no honor in combat.
In September of AC 195, Treize resigned in protest over Romefeller’s increased support of mobile dolls. OZ was soon split into two factions: those loyal to Romefeller and those loyal to Treize. In response to the escalating insurgency by the Treize faction, Romefeller launched a global offensive known as Operation Nova, unleashing legions of mobile dolls against Treize faction forces around the world.