Unification War

The Unification War (also known as the Metal Wars) was a conflict between the New United States and the Free States that occurred between 2069 and 2070.

Officially recognized as a war between the New United States of America and the autonomous Free States, the Unification War is also considered a corporate war by scholars due to the essential participation of the competing Militech and Arasaka corporations. The conflict is also referred to as the Metal Wars due to the wide use of cutting-edge military technology, including vast amounts of armored vehicles such as panzers.

Early war
In 2069, the recently elected president of the New United States, Rosalind Myers, presented a unification program to extend federal rule over the autonomous separatist Free States under the pretense of strengthening the nation. Most of the those states opposed unification, leading to an inevitable conflict.

The NUSA, backed by nationalized Militech forces and the support of the former Free States of Southern California and Utah, declared war on the loose alliance of Free States: Colorado, New Mexico, Wyoming, Montana, Arizona, Nevada, and Northern California. Washington, Oregon, and Idaho remained neutral in the conflict at the price of making some concessions to the federal government. The Republic of Texas didn't side with the NUSA or join the alliance, instead had its own agenda and opposed both sides. Other non-mentioned Free States, taken by surprise by the NUSA's aggression, surrendered immediately.

The New United States was the first to act, striking at the states of Colorado, New Mexico, Wyoming, Montana and Arizona; aided by South California and Utah.

Seeking to re-establish its influence on North America, the Arasaka Corporation took the opportunity to secretly financed the Free States. Despite the new weapons and the corporate "security advisers," the alliance was pressed hard by the NUSA military; made up mostly of Militech's advanced technology and backed up by the rest of federal states.

The conflict kept escalating, leading to the Battle of Ridgecrest, in South California, which became the bloodiest fight in the war, with at least 3,078 people reported dead in one day.

Late war
By early to mid 2070, the federal forces had occupied every warring Free State with the exception of Texas and Northern California, though the latter's capital city of Sacramento was carpet-bombed during the night of June the 6th, causing many more casualties in the war.

To the southwest, bordering with the NUSA-allied SoCal, the NorCal metropolis of Night City had avoided the fighting so far by maintaining a position of neutrality, but only barely. Its citizens had been holding their breath as they waited for an invasion from their neighbor, and fears of such an attack caused corporations to pull all of their funding from the ongoing development of the Pacifica District, which soon became a battlefield between Arasaka and Militech. Some parts of the district were occupied by a NUSA detachment led by Colonel Hansen.

The situation in NC was bad enough that the USSR sent humanitarian help, nonetheless, independent observers claimed it was instead trucks of weapons what the Neo-Soviets had sent. To make matters worse, Night Citizens who had fled east to find refuge in Texas found its borders officially closed to them.

At a later point, another NUSA Army division was sighted approaching the city outskirts. However, they were prevented from invading Night City thanks to the actions of then councilman Lucius Rhyne, who used his decade worth of contacts in the Night City Council and asked the exiled Arasaka Corp for protection. In June 12, an Arasaka supercarrier showed up in Del Coronado Bay. Just a few hours later, the NUSA retreated from the area.

FIA agents had infiltrated Night City as well, but after the previous events, they were called off by President Myers.

Treaty of Unification
Following Arasaka's intervention, all parties were unwilling to commit to a full-scale war, and soon afterwards a peace treaty was proposed. President Myers agreed to the terms, as the NUSA was not able to afford the costs of such a conflict escalation. Signed in Arvin, South California, the Treaty of Unification (or the Arvin Accord) signalized the end of the war.

The treaty ensured the Free States would remain autonomous, though they had to extensively cooperate with the New United States, agreeing to participate in the federal government and cease hostilities among themselves. Night City managed to maintain its full autonomy, seceding from both the North Californian and NUSA laws and governance, becoming an international free city. Texas didn't participate in the signing, remaining a fully autonomous and hostile state to the NUSA. Arasaka was the one who gained the most, as the ban imposed after the Fourth Corporate War was lifted and the corporation was able to return to North America.

The peace treaty was unsatisfactory to most parties but was considered preferable than continuing the war and risking another global crisis. Despite this, both sides claimed victory. The Free States emphasized they had preserved their independence, and the NUSA boasted that they were closer than ever to reunify the divided American people.

Aftermath
Night City's newfound freedom came at a price, as corporate interests were once again permitted in the city borders. This lead to an increase of corporations' influence, and to their pumping money into revitalizing the metropolis in order to establish a foothold on the West Coast. The symbolic capstone of these events occurred later that same year, when the newly elected mayor, Lucius Rhyne, and the city council allowed Arasaka to build their new American headquarters downtown, on the site where the previous one had been destroyed in 2023.

A concrete border wall between South and North California was built after the War by the United States. Despite not being a part of NorCal anymore, the NUSA still extended the border through the Badlands south of the city.