My predictions for the future of the Capital Wasteland and the wider implications and prospects for the Fallout series.

Victorious in the battle for the capital wasteland with the enclave now in ruins and the super-mutant threat largely contained; the east coast Brotherhood of Steel would effectively assume de facto control over of the D.C. area in the aftermath of Fallout 3. Under the stewardship of Elder Lyons the Brotherhood's new mission on the east coast of overseeing the reconstruction of the capital had more to do with the Brotherhood's rather more longstanding traditional goals of seeking to maintain monopoly control over uncovered pre-war technologies than mere noble intentions with the end goal being to re-establish a spiritual successor to the US Army/Pentagon.
While de facto rulers of the capital wasteland and by default the country I don't believe the east coast Brotherhood of Steel's ambitions extended much beyond their techno-religious philosophical leanings, certainly not to the same extent as the Enclave with their grand designs of statehood. Going against conventional wisdom of the Brotherhood I believe Lyon's saw it within the narrow scope of their interest to pacify the citizens of the wasteland rather than risk another protracted and costly war as they had in the core region which would leave them in a much weakened position to defend against encroachment from outside forces and counterproductive to stated longstanding objectives.

So to win over the hearts and minds of the natives project purity was essential, and going forward so would be the clean-up and reconstruction of the infrastructure and the reinstitution of the rule of law. Authoritarian topdown control in the past had given rise to the enclave and nuclear war so I believe would be perceived as neither favorable nor desirable by the public or the Brotherhood and any attempt to initiate any perceived dictatorship would probably met with anger, resentment and violent hostility and the breakdown of relations, not to mention the Brotherhood's complete lack of political aspirations and wider residual sense of detachment and isolation from the local irradiated inhabitants.
In this regard I believe locals will be permitted near-total independence over their own political and economic affairs (where those interests don't interfere with BoS's) and the reinstitution of democratic institutions will largely be handed over with impunity to Rivet City's local academic community with wider participation from wastelanders enforced by Brotherhood and Rivet City join security forces. In this way the Brotherhood will be viewed as liberators and supporters of democracy, even at times with an uneven and heavy hand.

The capital preservation society as the upmost authorities on u.s. constitutional law would be likely candidates to play a key founding role in the framing of the constitution of a new District of Columbia republic and would probably go on to form the basis of the new republic's supreme court. Further amendments would likely grant equal rights to all citizens (e.g. ghouls), freedom of religion (e.g. church of atom), and emancipate all slaves (e.g. paradise falls) drawing direct inspiration from the original founding documents themselves, e.g. federalist papers, etc. For as long as these conditions of relative freedom, liberty and security endure the new republic will likely to grow to become a regional power attracting both immigrants and neighboring hostility. Economic power would probably preclude greater territorial expansion of the Brotherhood of Steel who would benefit enormously from mandatory state taxes and subsidies, etc.

The east coast Brotherhood by this time will have amassed an enormous amount of power easily comparable to that of any of the core region's major powers and within 50-100 years would probably look outward and start conquering new lands whilst simultaneously realizing the importance of the D.C. region's continued financial backing (and hence it's protection) to their present military industrial capabilities having now started developing technology of their own. Economic development will have rapidly expedited D.C.'s transition by this time into a thriving cultural metropolis and the stigma of once being the capital wasteland will be well and truly gone. The west coast Brotherhood are now are a distant poor relation.

Enter Fallout 4. The Brotherhood's northeastward expansion into the former northeastern united states territories. Here they will meet old foes and new ones alike. The Commonwealth is now overrun by the android rebellions while the Enclave are now forging uneasy alliances with unlikely bedfellows (feeling threatened by the sudden emergence and strength of the EBoS) along with numerous other new contenders on the regional scene are now all vying for control of the former New York state. The Brotherhood leadership at this point are no longer content with merely restoring pre-great-war relics now that they have the acquired the necessary technological capacity to create their own new superior technologies and henceforth are now focussed on the new primary goal of becoming the region's single dominant military power thereby rightfully securing their claim/legitimacy as the United States Army.
Under such a scenario the Brotherhood's leading role could potentially be reversed from Fallout 3 as the BoS could rightfully be viewed in Fallout 4 under such a scenario in a different light; in some case as an evil hegemonic invading army who threaten the existence of many newly formed small independent states - blurring the line between good and evil. Or as a misunderstood bunch of crusaders who want to liberate these peoples from the dangers of the Enclave and beyond, or a bunch of thieves/hired mercenaries attempting to steal the resources of the indigenous peoples by force at the behest of big business in the capital - in some cases propping up cruel regimes, etc. In such an event you'd surly be able to take sides and a number of potential outcomes could ensue.

A) The Brotherhood of Steel could fail to secure domination of the region and major rivals could threaten to engulf the entire region in another bloody civil war potentially risking yet more nuclear annihilation.You may end up determining the players.

B ) East Coast Vs. West Coast. The Brotherhood prevail and become the single-unified-military-fighting-force in the east, representing a major threat to the core regions major powers and strategic interests and a power struggle ensues - the midwest becomes an unstable power vacuum as the west unites in the face of any perceived challenge. It would be hilarious if they were all commies!

C) The Brotherhood could lose the region entirely as another power gains primacy and may be forced to retreat all the way back home to Lost Hills humiliated as losers.

D) Stalemate in the northeast = New Miami sunshine! The BoS find themselves in a position whereby they must expand quickly southwards in order to consolidate enough power to counteract growing momentum of a perceived threat of Northern aggression quietly encroaching on their territorial boarders. Eventually a more powerful BoS might then be able to divide and conquer the entire region followed by B ).

E) The Brotherhood's respective splintering into different sects separated by vast distances and the subsequent divergence from their original mission precipitates an eventual civil war, with outcasts, midwesterners, east and west cost brotherhood factions all taking sides.

F) A future without the Brotherhood playing any kind of significantly over-arching role.

G) You decide.

Nice theory, some of it makes sense but I think that Elder Lyons will not try to become a dominant military faction though, have you considered the outcasts having been able to contact the west and tricking them in to attacking the east.

Well my thinking was the east coast Brotherhood of Steel would probably anticipate the likely economic benefits of a thriving unified D.C. state as their army by extension thereby entitled to wealth of the states funds and resources or at least partial funding for their reconstruction effort so for the time being reconstruction would likely dominate their agenda into the next century - certainly under the current leadership of Elder Lyons, I agree.

Even under the noble leadership of Elder Lyons however the Brotherhood east and west would very likely get behind any real local political unification process in the capital wasteland for practical reasons despite lacking any kind of political will of their own and the Brotherhood's backing all but guarantees it's chance of success.

The reasons being to stabilize the region and keep outside influences and competitors (keeping all foreign and domestic enemies) from getting their hands on any remaining uncovered pre-war technologies. As a perceived instrument of the state this would all but guarantee assumed monopoly control over any remaining artefacts. If they were true to their word in truly wanting to protect the peoples of the wastes then this kills two birds with one stone.

As previously stated the potential to exploit such a source of strategic power (diversion of once potentially unimaginable sources of income and resources into their scientific pursuits) would be key to restoring the Brotherhood's diminshed status as a major power nationwide. Even if Lyons resisted the big whigs at Lost Hills would no doubt come down on him like a ton of bricks and attempt impose consensus and assume control of their operations. The trouble comes later generations down the line when Lyon's vision is all but fulfilled and the in their work in the D.C. area is done.

By which time the pentagon which is symbolic of the Brotherhoods longstanding goal to become the rightful successor to the United States army will also be fully realized. The only logical conclusion is to take this further. I predict that Lyon's idealism will be supplanted by realism as younger leadership becomes corrupted over time by the religious doctrine of subordination to the high elder ruling class that Lyons once railed against.

The high elders upon eventually re-assuming control of the operations on the east coast either directly or indirectly through intermediaries will prescribe a return to the re-enactment of the scriptures after being merely temporarily halted in their progress by the NCR, Enclave, etc. The outcasts and other factions will probably fall in line behind the leadership class of Lost Hills central command now that they possess potentially the necessary power to enact their shared vision prescribed in the scriptures. Having not read those scriptures I can only speculate... my inclination is military domination of all rivals, acquisition of their and any and all advanced technology with the end goal of taking back the continental United States as the only legitimate heir to the United States military.

Naturally a united Brotherhood of Steel will be antagonistic to the main powers in the core region but will lack the current military capacity to take them all on without significant expansion, consolidation and projection of power in the east. Knowing that the east is Bethesda's domain naturally I think it's only logical to assume Fallout 4 will all about the fall out after Fallout 3, predictably the Brotherhood's expansion into the next likely candidate for the Fallout treatment, namely New York City, probably 50-100 years after the events of Fallout 3.

Well I think with the losing ground in California to the New Californian Republic that the East Coast Brotherhood of Steel will likely fall due to other factors.

It is likely that the rapidly prevailing and expanding New Californian Republic will seek interests in the East and if the Brotherhood shall fall in the West the East being smaller in size. May abandon their position as they see that the Lost Hills is doomed.

I suspect a demise of the Brotherhood like the Enclave , as the failing Empire could lead to chain of failures should the Brotherhood of the East be unable to fight the either native forces of the Capital Wasteland or if the NCR should take hold and defeat the remnants of the Brotherhood.

Well, the only reason as I'm sure you know the NCR prevailed over time in the fight was because the Brotherhood of Steel on the west coast outright refused to replace their dead; as sub prime-normals at the time were viewed as sub-human. The NCR would have been otherwise annihilated as they had been for years before BoS numbers started to slowly decline - such is the strength of their respective edge in warfare capabilities.

The reversal of this policy on the east coast effectively allowed the Brotherhood under Lyons to defeat not only the Enclave but a super-mutant army simultaneously, so I wouldn't be so careless as to write them off If I were you.

Without the tactical advantage of being able to replenish their ranks at the expense of the Brotherhood the NCR are just another (if well organized) poorly equipped (by comparison) traditional standing army lacking power armor and BoS/Enclave-grade high-tech precision weaponry and the finer points of their current status are yet to told.

But I agree they are a formidable foe not to be understated, but Caesar's Legion's are likely hold back any immediate plans of expansion beyond the core region into the next century (2280-2300).

Yes that is true and makes sense. However the Brotherhood is military flawed since its incapability of replacing its numbers its military and being very expensive to do so will slowly decline. If you look at historical examples of this is Napoleon's Campaigns in Russia was disastrous as the Grand Armee had little resources to supply it's declining numbers as the Russians burned and destroyed all things of value to the French. And as the French army died, Napoleon could not replace his entire army and have them be as powerful as before and that led the destruction of his new army and the fall of Paris. Same happened with the Germans in WWII, their defeats and incapability to supply themselves led to the fall of the German Army.

The New Californian Republic have an extreme advantage as they have superior numbers by far, I don't recall how large their army is but I am guessing around or larger than 50,000? Those numbers are a bit extreme but the NCR does have a population of 700,000+. And the NCR is rapidly expanding leading to more recruits every day.

We already know that the morale of the Brotherhood is at an all time low as the lower ranking soldiers deserted their posts or joined the NCR. An example of this is that the Hoover Dam was in the Brotherhoods hands until they joined the NCR (the Brotherhood retook this but it was short lived as the NCR recaptured it).

And I expect that once the word of the failure in the West will lead to either the Elders of the East to either help their comrades or sit out in the East and rebuild their monopoly and being an Elitist group it will difficult to do.

In my opinion if The east Brotherhood and NCR were to meet I think they could strike a coalition since the East is protagonistic and also the East could hire from the DC wasteland. Since they have a monopoly of clean water, enclave,technology and if they build liberty prime again, then all the more reason to be allies. But this depends on who becomes the leaders of these factions.