Brotherhood War

The NCR-Brotherhood War, referred to simply as the Brotherhood War by citizens of the Republic, is a major conflict between the Brotherhood of Steel and the New California Republic that has thoroughly affected New California as well as areas around it, shifting its fragile balance of power.

Background
The roots of the war lie in the decline of the Brotherhood of Steel between the eldership of Rhombus and the emergence of the New California Republic as the dominant power in New California.

The Republic refused to accept the policy the Brotherhood attempted to impose on it, which resulted in a military confrontation. Although the NCR tolerated Brotherhood presence as late as 2241, by the late 2250s or early 2260s, military clashes between the republic and the Brotherhood were already commonplace and consuming lives.

Course of the war
This gave way to a long and bloody war that took a considerable toll on the NCR Army and the Republic itself as well as the Brotherhood. During the early years of the war, the Brotherhood was able to inflict heavy losses on the NCR, achieving numerous victories and successes in the opening stages of the conflict. However, despite enjoying a huge advantage in individual training and equipment, the Brotherhood was unable to match the New California Republic's manpower and ability to replace losses, and the tactical and strategic flexibility it provided. Eventually, the Brotherhood was forced into retreat and hiding. At least six chapter bunkers were wiped out by the Republic, four destroyed by the Brotherhood in a last-ditch attempt to deny them to the NCR.

Eastern front
Although hostilities continued in New California, the Republic recovered and focused its efforts on expanding eastwards, into the Mojave Wasteland and Hoover Dam. Elder Lyons mentions turmoil, in that "the Brotherhood of Steel has been struggling for years, both here and back home." The subsequent occupation of the Dam in 2273 brought it in conflict with the Mojave chapter of the Brotherhood, which operated unrestricted in the region for years. After two years of guerrilla skirmishes instigated by the Brotherhood, the NCR launched Operation: Sunburst to neutralize the chapter in a single, pitched battle at HELIOS One. The indefensible nature of the solar power plant, inexperienced soldiers, limited manpower, and poor tactical decisions made by Elder Elijah were ruthlessly exploited by the republic and its commanders. Concentrating a force that outnumbered the Brotherhood defense by a factor of between 15 and 20 to 1, the Operation was a tremendous success. The Brotherhood was routed, losing half its manpower, including over a half of its veteran knights and paladins. The survivors retreated to Hidden Valley through the McCullough Mountains and enacted a strict lockdown.Fallout: New Vegas Official Game Guide Collector's Edition p.43: "Brotherhood of Steel" "The Brotherhood of Steel is a militant organization devoted to the preservation of pre-war technology and human knowledge. Their professed mission is to preserve pre-war technology and human knowledge for the benefit of future generations. In practice, its definition of technology is strangely selective, ignoring basic but potentially useful technologies (genetic modification of crops and civil engineering, for example) in favor of combat technology such as energy weapons and power armor: and even now, nearly two centuries after the Great War, the Brotherhood zealously restricts the use and knowledge of such technologies to its own membership. ''The Mojave Brotherhood operated freely amid the Vegas wastes for several years, carrying out many reclamation missions without serious opposition. The balance of power shifted in 2251, when a large contingent of NCR troops entered the region and occupied Hoover Dam. Conflict was inevitable. Nearly two years of guerilla skirmishes culminated in a pitched battle at HELIOS One, a solar energy plant the Brotherhood had been refurbishing for several months with the goals of bringing it back online and activating its hidden offensive capabilities (the ARCHIMEDES II death ray). The battle for HELIOS One (Operation: Sunburst) proved a disaster for the Mojave Brotherhood. More than half its Paladins and Knights were killed. The chapter's leader, Elder Elijah, disappeared without a trace. The Brotherhood was driven from the facility, which suffered extensive damage. Survivors retreated to Hidden Valley.'' ''Since that defeat, the chapter's leader, Elder McNamara, has restricted activity outside the bunker to occasional reconnaissance missions and high-value raids. All operations take place at night, and engagement of NCR forces is strictly forbidden. Though the Brotherhood's ascetic lifestyle has prepared its members for a sequestered existence better than most, the passivity of their current situation has proved highly stressful."'' (Fallout: New Vegas Official Game Guide faction profiles) As they hid, the republic increased its military presence in the Mojave fivefold.

Notable battles
Operation: Sunburst, a pitched battle where the Mojave chapter lost control of HELIOS One and suffered crippling casualties amounting to half the chapter and half its knights and paladins.

Outcome
Hostilities continue in New California as of 2281, although it is no longer considered a priority conflict for the NCR. After years of warfare and attrition, the Brotherhood has been forced into hiding and retreated into their bunkers. Veteran commanders of the Brotherhood War have been reassigned to other fronts, with the most prominent of those being Colonel Cassandra Moore, with four tours to her name, a legendary status among the troops, and tasked with effecting the annexation of the Mojave through any means necessary. Victory came at a significant cost in men and materiel, especially during bunker assaults, when platoons of troops were lost to eliminate a stronghold.

Meanwhile, the Brotherhood is dying out, in hiding, with some of its most talented members going rogue instead of aiding the Brotherhood. Due to the ongoing hostilities, the NCR is willing to continue its pursuit and elimination of the Brotherhood. However, in the interest of strategy, it is willing to form alliances with surviving chapters, provided they are not at crossed purposes.

By 2287, Lost Hills, the heart of the Brotherhood out West, remains under Brotherhood control and the elder council remains in power. The elders continue monitoring far flung chapters, reestablishing contact with Lyons' chapter in D.C. and reintegrating it after the rise of Arthur Maxson. Cults dedicated to the new Maxson started to emerge on the West Coast, routinely suppressed by the council.

Appearances
The NCR Brotherhood War is mentioned only in Fallout: New Vegas.

Behind the scenes
(Josh Sawyer on forums.somethingawful.com)
 * The developers have commented on the backstory of the conflict.    Joshua Sawyer: "It happened during the BoS-NCR war. I believe Alice McLafferty mentions it, but I'm not positive. She doesn't detail the events in this much detail, but here they are: The attacks caused NCR citizens (and others who held NCR currency) to panic, resulting in a rush to reclaim the listed face value of currency from NCR's gold reserves. Inability to do this at several locations (especially near the periphery of NCR territory where reserves were normally low) caused a loss of faith in NCR's ability to back their currency. Though NCR eventually stopped the BoS attacks, they decided to protect against future problems by switching to fiat currency. While this meant that BoS could no longer attack a) reserves or b) the source of production (all NCR bills are made in the Boneyard), some people felt more uneasy about their money not having any "real" (backed) value. This loss of confidence increased with NCR inflation, an ever-looming spectre of fiat currency. Because the Hub links NCR with the Mojave Wasteland and beyond, the merchants there grew frustrated with NCR's handling of the currency crisis. They conspired to re-introduce the bottle cap as a water-backed currency that could "bridge the gap" between NCR and Legion territory. In the time leading up to the re-introduction, they did the footwork to position themselves properly. If some old-timer had a chest full of caps, they didn't care (in fact, they thought that was great, since the old-timers would enthusiastically embrace the return of the cap), but they did seek to control or destroy production facilities and truly large volumes of caps (e.g. Typhon's treasure) whenever possible."
 * The conflict was intended to be content in the canceled Van Buren.