Since the middle of the 20th century a small core of the US government and military have been in contact with and later working with small groups of aliens in what was then called Area 51. The government denied the existence of this base for decades, even though photographic proof of its existence was out and available to the public. The original plan for this area was to study and learn the more advanced alien technology for use in military applications. Later in the 1970's they began to formulate a plan to introduce the general public to the fact that there is life elsewhere in the universe. Preparations were made, using the popular media of the time, to slowly expose the population to the thought of interaction and co-existence with extra-terrestrial life forms. Each time that a date had been set for the "first contact" to occur, world events would conspire to postpone it. This continued for almost a century until, in 2098, the great war struck the nations of the earth.
For three years before the great war and the coming of the Rifts, the USACM militaries had been moving all of their classified "black" projects as well as the bulk of their R&D scientists to the protection of the 5 secret underground installations in the state of Nevada. These five bases were built in co-operation with the alien races. All these were located in Nevada due to its sparse population.
When the nuclear missile exchange began, these bases had enough defensive fire power to thin out the number of warheads that were targeted on these areas. In the initial attack many EMP devises destroyed the electronics of some of the defensive anti-missile vehicles and weapons. At this point the bases were forced to expose their true nature and purpose. For the first and only time in recorded history, all five bases rose and broke through the surface. Each was a five mile wide disk shaped starship capable of supporting 250,000 people on an indefinite journey through the cosmos.
Once free of the sandy desert the ships powered up their weapon systems and systematically shot every remaining missile from the Nevada sky with the exception of a group of warheads that had already hit in and near the Las Vegas area, including the Hoover Dam and Nellis Air Force Base.
The ships were getting ready to return to their previous positions underground when the first tremors from the massive nuclear strike on the San Andreas fault, near to the city of San Francisco, caused an earthquake with a magnitude 15 on the richter scale. The quake spread from the epicenter across the western states flattening any remaining surface structures and killing most of the surviving people for over a thousand kilometers in every direction. The tsunami kicked up by this quake shattered some of the Hawian islands and caused massive flooding of the coastal regions of asia and Australia. The few surviving seismographs in the Nevada desert registered the shock wave as 12.6 to 10.8 throughout the state.
Once the aftershocks dropped down to less than 10.0 the starships returned to their underground locations. The network of tunnels that had connected the bases was completely destroyed and had to be rebuilt. Over the next few days radio contact was made with surviving long range nuclear bombers who began to fly to and land at the five bases, using the flat terrain as makeshift runways. In total 200 B-3G's and B-4A's survived and were divided among the bases. In a surprising twist 150 Russian bombers already over the USACM borders made radio with the bases and surrendered their aircraft and nuclear missile load for asylum and a chance to live through the war.
In the early days, right after the coming of the Rifts, while the bases were rebuilding the network of tunnels, recon units from the bases were sent out to find out what remained of the world they new and what had happened to it. These units were charged with the task of checking the surrounding states and bring back any survivors if they found any.
After the first week of battling the sand storms and finding a handful of survivors, the ground troops were recalled and only areal reconnaissance was performed.
The first contact with DB's other than the aliens that already lived on the starships was with a group of demons that came from a rift in death valley. A reconnaissance plane, seeing a bright blue light in death valley, flew lower to investigate. The pilot flew around what was later to be realized was a large nexus point and spotted hundreds of beings on the ground.
Taking no chances with the unusual group, 200 troops and 6 squads of GB-10 Glitter boy's were airlifted to an area 20 miles away from the sighting to further investigate. Once this force was within 3 miles of the presumed point of contact they were attacked by the first wave of demons. The fight was short but brutal. In the end less than 40% of the troops made it back to the extraction point and two squads of G-bees were destroyed while covering the retreat.
The waves of demons was only stopped from advancing into Nevada by a massive offensive operations involving long range artillery and saturation bombing of the demon hoards as they tried to cross the border. The loses to the demons was tremendous but they only stopped from advancing when a demon far larger than most ordered them to return to death valley.
Since that time there have been numerous battles with the demons, but none as bloody as that first encounter. The only thing that counteracted the growing numbers of demons was the fast advancement of aircraft and weapons technology. Only a very few of these demons are capable of flight. The first and only encounter with one of these winged-demons ended with that demons death, but only after two squadrons of fighter jets engaged the demon. Even then the demon was only 10 miles from the Sentinel-1 base in Area-51.
The demons continue to try and move in on the Nevada territory but only to prey on caravans and travelers that travel too close to the border of death valley. More and more of the demons are traveling south toward the vampire kingdoms. The demons find the Vampires far more entertaining to fight and they prefer their taste over normal humans.
Once the migration of the demons started and things returned to what could be called normal for that area, the scientific and military leaders of the five starships got together to discuss their future. After two months of planning and discussions the formed the ruling council of the Desert Alliance, whose structure remains in place today. They also formulated a 500 year plan to gather as many survivors as they could and leave the earth to find a more hospitable place to live. Until the preparations for the exodus were complete the Alliance would strive to make it as safe as possible for those in their care in the present hostile environment.
Using the production facilities that the bases were equipped with, they continued to advance their already state-of-the-art arsenal of weapons and vehicles. Everyone who was living on the bases became a member of the military and the research scientists also became teachers of the children. The Alliance became completely self reliant to survive in the new world.
The first stage of the Exodus plan involved creating a buffer zone around the bases to better protect them from any hostile forces and until they were ready to leave, the Alliance would have to protect themselves as best they could by advancing their technology.
The Alliance started to expand as far as they felt they could control with the resources they had available. First they expanded west to the pacific coast. Here they encountered numerous Dbees who now inhabited the sierra nevada mountains, the only hospitable land that the Alliance would ever find in their expansion.
To the north they found what can only be described as a wall of radiation and volcanic activity that spread from the coast of Oregon across the northern parts of Idaho and eastward to the american prairies.
To the south they stopped at what used to be the american / mexican border in Arizona. In this region they made sure to give the demons a wide berth for when some of their number migrated south. Occasional confrontations with these demons still occur but every effort is made to avoid contact if possible.
To the east the Alliance stopped part way though the vast desert that stretches across the plains. They set up recon posts along the Rio Grande river in new Mexico then north through colorado and parts of wyoming, ending at the radiation wall of the north west.
The Alliance has maintained these borders with hidden outposts that are scattered all along the borders at all four points of the compass, including the California coast.
When it was realized that the DA was technologically more advanced than all but a small few kingdoms by almost a hundred years they adopted a policy of "non-interference" and "watch and wait". The DA began to develop more advanced aircraft and vehicles to fight the demons and any other foe who they may encounter in the future. Since a large portion of their previous R&D engineers were trained to create aircraft using the new technology that they had learned from the Aliens, who were now a major part of the DA, they continued to build a newer and more advanced airforce to protect they're kingdom with.
Although they have extremely advanced infantry, power armor, robots and other vehicles, the bulk of their military is composed of aircraft. This gives them the ability to control the large area that they do and since they have few rivals in the air they have maintained these borders up to the present day
Over the first two hundred years settlements of humans and D-bees began to form all over the Alliances territories. Since the Sentinel bases, air bases, and outposts were hidden, the Alliance has left these settlements to develop on their own. The Alliance has watched the development of these settlements with interest and used them as a gauge to what was going on in the world around them. What they discovered about the other Kingdoms of North America both surprised and frightened them. The Alliance provides protection in the form of a ghost military that show's up when needed then departs when the threat has past. The DA has also extensively covered the American continents with their reconnaissance aircraft to add to this knowledge as well as gaining first hand information from other sources (explained in foreign relations section - which I'm still in the process of writing). Most of Europe, Africa and the pacific rim have also been covered by the ariel reconnaissance but not to the extent of North and south America. Numerous aircraft were lost in the initial stages of the DA's quest for knowledge until the Aurora-3 was developed in 20 PA.