Brotherhood War

The NCR-Brotherhood War, and often referred to simply as the Brotherhood War by members 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. Confronted with an expanding nation state, the Brotherhood adopted a reactionary policy, attempting to seize any advanced pre-War technology, limiting and controlling access to such technologies throughout the region, particularly energy weapons.

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
The rise of Jeremy Maxson to the position of High Elder in 2231 represented a change in the Brotherhood's course. As his term continued, Maxson gradually adopted a more direct, confrontational policy of wrestling technology from the hands of wastelanders (the "lesser people"), in a bid to restore the Brotherhood's privileged position in the wasteland. The deterioration in relations between the Brotherhood and the republic was gradual, but it eventually devolved into war and by the late 2250s/early 2260s the Brotherhood clashed with the republic over technology.

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 tremendous losses on the NCR, almost winning the war and avoiding a protracted conflict altogether. 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.

Economic hardship
The NCR suffered primarily on the economic front. When the Brotherhood could not counter the republic's military advantage, it attacked the gold reserves that backed the New Californian dollar. As the raids intensified and gold became unavailable, destroyed or rendered useless by Brotherhood operations, NCR citizens panicked and rushed to reclaim the listed face value of currency from NCR's remaining gold reserves. Since the NCR was unable to realize these withdrawals, particularly towards the frontier, value in their currency considerably dropped. To protect against actual economic collapse, the NCR government abandoned the gold standard and established fiat currency, not payable in specie. Since then many wastelanders lost faith in it as a medium of worth, both as a result of it not being backed by anything but the government's word and the inevitable inflation. In response to the loss of faith, merchant consortiums of the Hub established their own currency, the venerable bottle cap, backing it with water (exchanging a standardized measure of water for caps). The merchants conspired to reintroduce the bottle cap as a currency out of frustration stemming from NCR's ineptitude in handling the currency crisis. "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." --J.E. Sawyer src

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. Unexpectedly, the 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, 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) Note: The date of the NCR occupying Hoover Dam is wrong, as the first NCR Rangers scouted Hover Dam in 2273, with the deployment following in 2274; article dates have been corrected to match. And 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
The war is currently still ongoing. Colonel Cassandra Moore states that she recently returned from a tour against the Brotherhood and has now been deployed to the Mojave. However, the state of affairs is largely in the NCR’s favor. The Brotherhood has been forced into hiding by retreating into their bunkers. Veterans of the Brotherhood War can be seen leading the republic's efforts against its other enemies. The most prominent of those is Colonel Moore, with four tours to her name and a sizable reputation among the troops. Meanwhile, the Brotherhood is dying out, in hiding, with some of its most talented members going rogue instead of aiding the Brotherhood.

However, victory came at a significant cost in men and materiel, especially during bunker assaults, when platoons of troops were lost to eliminate a stronghold. Despite that fact, the NCR is willing to continue its pursuit and elimination of the Brotherhood, although it is not above forming alliances with surviving chapters, provided they are not at crossed purposes.

By 2277, the status of the Brotherhood out West is largely unknown. However, with terminals stating that the west has started operations hunting down cultists worshipping Maxson, it seems like they are at least starting some semblance of operation on the surface once more.

Behind the scenes

 * Although the war was never explicitly mentioned in Fallout 3, Elder Lyons says that "the Brotherhood of Steel has been struggling for years, both here (Capital Wasteland) and back home (New California)".