NCR.
They're the only functioning entity that resembles a nation-state, their only problem is over expansion in the short term but that is excusable in NV since Hoover Dam is an emmesely valuable strategic resource that was under threat of falling to a rival power. They just have to learn from their ancestor: Conquest of North America is a slow, steady process.
I also find the accusations of corruption rich. Give one example of an expanding nation with colonial interests that wasn't heavily corrupt? Even at that most of the corruption on the frontiers of their territory and that seems to be the case with NCR.
Just as their capital was once a backwater and now isn't in NVs time so too will come the growth of re-civilization.
Caesar's Legion are just barbarians with a thin veneer of ideology hiding that fact. They're also a one-man entity that will not outlive that one man, everyone but Caesar is a barbarian LARPing as a Roman.
Brotherhood are too isolationist and too fixated on the ideological bent of hording technology and keeping it from everyone else. Their best best would have/ would be to merge with NCR and co-op their growing statehood to accomplish their ends with the means to do so.
House is your typical technocrat with promises built on sand. His premise of saving humanity has nothing solid backing it and is yet another one-man operation. He'd make it his way or let everyone burn and he can only live for so long, he won't be leaving behind anyone to fill his shoes no matter what he tells the protagonist.
Followers are ideological idiots who have no backing behind them to forge an emerging state and lack the means to do so, both psychically and mentally: They are completely lacking in ruthlessness which means they're nothing but their beliefs, fluffy thoughts.
This is the reason why the NCR is the only candidate: They're fighting to maintain enough of the Old World representative republic while conforming to the realities of the world they're in as well as being a rational nation-state and looking out fort their own welfare while expanding and guarding their interests with little regard to anyone that is unable to stand in their way.
Unless you choose Caesar's Legion, anyway. They don't believe in modern medicine, and they certainly don't want education. Cultural and societal regression, ho!
Like any militant ideology they'll only accept absolute conformity to it. Even if the Followers weren't a real threat, they'd still be different and thus dangerous. It doesn't help that they're peaceniks and the direct opposite of the Legion in every way.
Like any pacifistic movement facing a violent and amoral enemy, they'd only make a world in which there weren't any Followers.
(your opinion may vary as to whether they are motivated by greed or have more benevolent intentions)
They're a democratic nation-state.
They do it for both reason you've listed.
Favorite main story choice "faction": Independent Vegas, and not with me as some sort of dictator. I go my own way, and Vegas goes its in turn.
Only hope for New Vegas in that choice is if they get things together and become a new, expanding power like NCR. If they don't then then the NCR will recover in time and extend into the Mojave better prepared. Like the Boomers against the Legion, it won't matter how many robots they have if it comes to a war of attrition.
I doubt that such an independent power would last, the population is simply too fractured, and as House correctly calls them, are merely the barbarians of the wasteland given the creature comforts of the Old World. The simply lack the education to be able to forge a nation-state in the immediate future with NCR being a neighbour and having over a century of time to build a solid foundation to work on.
the great khans- sure they sell drugs and supply the fiends(before i kill the fiends leader) but you can convince them to make helpful medical supplies too
if they were gone some one worst could replace them. yeah they are not good or evil
Like all barbarian tribes they only exist a the vacuum of power. Either one forms a nation and takes them over or a preexisting power like NCR, which was formed from such barbarians, will come along and integrate them into their country, one way or another.
It's heavily implied in both Fallout 3 and Fallout: New Vegas that China was the one who initiated the nuclear war. Considering they were the aggressor against the United States in the Resource Wars as well, it isn't much of a surprise. Had it not been for China's actions, the United States likely would have continued onward just fine.
Mutually Assured Destruction sucks. Massive understatement. But it's used as a deterrent. If China hadn't launched, the United States wouldn't have retaliated. It's the sort of situation that MAD is supposed to prevent (and so far has in real life).
If FOs back history was based in reality then the US would have been the first to launch, in retaliation for the invasion of US territory.
Nuclear deterrent severely limits a nations ability to expand because they have to factor in other nations nuclear weapons, but it guarantees the integrity of their nation: Invade us and we launch.
Both nations invading each other wouldn't have happened. Not a single Chinese boot would touch Continental North American soil because the End of the World would have come once it was clear that the Chinese invasion fleet could not be stopped from making landfall.
However my favorite faction was the Boomers. They don't concern themselves with constantly conquering or claiming shit (though then again I guess that's because they don't need to, you can see why the NCR and Legion do what they do), they arm themselves with enough exploding shit to fight and win a small war and hole up in an old air force base with a fuckton of artillery, shelling anything that comes nearby.
Now THAT'S practicality!
Boomers are foolish isolationist like the Brotherhood, only far weaker than them. They're strong, but too weak to remain an independent power anymore. Placed between two powerful states they no room to maneuver. They either must join one or get wiped out should the Legion win because they wouldn't tolerate such a powerful neighbour.
This is very reason that gets the Boomers to side with whomever the protagonist tells them to.
I like the legion. While they may be rapists and slavers they actually protect their citizens, no matter how far their empire reaches, and they care about everyone not just one city, and they are not as corrupt and stupid as the NCR. I will update my post with more details later.
My immediate thought reading this naivety was this quote:
?Wherever there is a jackboot stomping on a human face there will be a well-heeled Western liberal to explain that the face does, after all, enjoy free health care and 100 percent literacy.?
― John Derbyshire
Caesar cares about everybody, he cares that they do what they're told, or else.
He is no different that any other charismatic authoritarian leader.
The NCR is fine (in theory), but they only emulate the past. They don't really understand it, and they will fall.
NCR's heart is in the right place. You do what you can do.
One comes before the other: Before they can prevent themselves from repeating those mistakes they have to create a stable enough nation to even begin to work on the major minor details, much less avoiding.
For now they're busy dealing with the challenges reality is presenting them NOW.
What you're asking of them would be to criticize the United States of the mid 19th Century for not dealing with the dangers that the United States of the mid-20th Century faced.