The "Outback" refers to the vast remote and arid areas inside the nation of Australia. Historically, exploration of Inland Australia has been sporadic, with the vast majority of the country's population living in coastal cities, such as Sydney.
Even by the time of the First Tiberium War, the Outback was not fully explored, except by the aboriginal people. Mining operations and tourism were the largest economic projects in the Outback, with such peculiar features as Ayers Rock (Uluru) being large tourist draws.
Following the global spread of Tiberium, the already inhospitable Outback became a virtual no man's land to GDI, who continued to control the large coastal cities. However, Nod began to see potential in the region. Although the sparse resources posed a challenge, the difficult terrain would more than likely cause GDI to overlook Nod activity. The Outback became a vast training ground for elite Nod troops. Notably, Intelligence Officer Ajay was born and grew up there. Renegade Black Hand forces under the charismatic Nod Confessor Marcion also relocated to the Outback following their break with the Nod mainstream and built up a large stronghold before Marcion was brought back to the fold by LEGION.
After the end of the Second Tiberium War, GDI began to build a presence in the Outback, although much of the region remained under the control of the Brotherhood. Notably, GDI built a secret laboratory in the desert, concerned with researching the potential of Liquid Tiberium. After the reincorporation of the Black Hand into Nod, Kane seized the opportunity to launch a surprise attack on the lightly defended facility. Although the lab did not contain a Liquid Tiberium Bomb, its destruction was still enough to greatly accelerate the spread of Tiberium across Australia. Because of the GDI willingness to covertly experiment with Tiberium with apparent disregard for civilian safety, and its failure to prevent the lab's destruction, many people began to question if GDI really had the interests of the people at heart.
By the time of the Third Tiberium War, GDI presence in the vast Outback remained few and far between. GDI stored surplus Nuclear weapons here where they thought Nod could never reach them. Meanwhile, Nod had significantly expanded it's presence, with Ayers Rock being a Nod Headquarters second only in importance to Temple Prime. However, this massive buildup drew the attention of GDI, and assaults on Ayers Rock began. Kilian Qatar, who commanded the Nod forces, requested backup, which was denied to her by Kane.
After the destruction of Temple Prime, Qatar recalled all remaining Nod military personnel to Australia, in a desperate bid to rebuild Nod's powerbase one continent at a time. First, GDI had realised that storing nuclear weapons in a remote area in the Outback was only cutting the base off from reinforcements, and sent a convoy to move the bombs to Sydney. However, Kilian, wanting to "level the playing field" now that GDI's Ion Cannon network was back online, sent some Elite troops into the outback to capture these weapons. Acclimated to the harsh terrain, these units quickly achieved their goal. However, at the same time, all of GDI's Ion Cannons in the Southern Hemisphere began charging. Ajay believed that GDI was planning on eradicating Nod once and for all, but instead, the Cannons began shooting at extraterrestrial spacecraft approaching Earth at extreme speeds.
The Scrin managed to survive this attack, however, and while the anxious Nod forces waited for evac, the aliens made planetfall nearby. Despite immense resistance from an enemy unlike any they had ever seen, the troops managed to hold out until Nod Carryalls arrived to retrieve the hazardous cargo.