If a few miners were to control a majority of the hash rate (say over 51% of the network)
What would stop them from colluding and trying to 51% attack the network?
Nothing. They can attack the network by mining on the same fork. The attackers just need to be in agreement.
What if the nation states try to stop Bitcoin by setting up their own farms and forcing the miners to adhere to their rules otherwise face death?
Nothing that they can do. With 51% attacks, you can't change the network rules. You would mainly only affect the transaction's confirmation and the ability to double spend.
Is there a backup plan for if Bitcoin goes down due to collusion? Or is BTC screwed?
It'll be pretty screwed. If BTC somehow gets attacked, the main damage would probably be done with the first double spend. Subsequently, people would probably realise that it is under attack and people would switch to another coin which has a different algorithm. This could render the attack pretty useless but it'll still cripple bitcoin.
But if BTC is the Global Reserve for all Cryptos , Wouldn't that hinder the entire crypto space? If i took down BTC value and made it plummet to 0 , all the other alt coins would follow , and if this does happen , then everything is worth 0 in fiat and 0 in BTC value because BTC no longer has value correct? If all of the money were to leave the ecosystem , then everything goes to 0 right?
What would stop them from colluding and trying to 51% attack the network?
The cost and the total available hardware.
The cost might not be a huge problem for a state but after the attack, what will they do to those ASICs that they've used for the attack?
But before that, where will they get the necessary hardware to gain 51%+ of the current network hashrate? Produce their own?
(
They will be needing more than half of the current hashrate since their own hash power will be added to the total).
Forcing the Pools (
not the miners) is more effective and cheaper than than "
setting up their own farm" but a lot harder to pull off.
I'm assuming at this point , that they would move to something that allows for ASICs for SHA-256...? But if Nation states were to extort or try to kill miners , we would be screwed if they managed to take over the network.
If a few miners were to control a majority of the hash rate (say over 51% of the network)
What would stop them from colluding and trying to 51% attack the network?
Economical rationality ?
Well if BTC is the digital gold standard by which all other Cryptos are backed by (Assuming DCR / BTC value) , It would make everything else plummet... in fiat and BTC value because they no longer have value thus nation states or governments which may have an interest in destroying the world of crypto (and the trustless nature of it) and bring on their centralized shitcoins that they control , maybe backed by gold or fiat money?