Capitalism is the extraordinary belief that the nastiest of men for the nastiest of motives will somehow work together for the benefit of all. - John Maynard Keynes
Competition is key. If they work together, it's to the detriment of all.
The problem of capitalism is that managing the competition becomes too complicated. Additionally, competition leads to price distortions. That can also become problematic.
The beauty of capitalism is that it rewards cooperation which makes it ugly because the lack thereof shows our deepest rifts.
This isn't complicated this is one of the most simple and most visible mechanism in capitalism. Even Keynes seen that, just his answer was unfeasible for a prolonged periods.
But how do you prevent the ones who regulate it from being corrupted?
By setting up a system that don't promote corruption nor require it, unlike capitalism which do.
Keynes answer was to make state regulate the above features of capitalism, but Keynes either from ignorance (hard to believe) or rather from utter idealism, ignored Marx and Smith analysis and warnings and put the regulation of capitalism in the hands of capitalist state. In effect, he tasked regulating those nastiest of men from OP quote to the very same men.
Recommended read: Lenin's "Imperialism, the highest stage of capitalism"
I really have to read it. But I don't question that the state will be corrupted. My question is how that non-corruptive system can be created. That's the tricky part.
Yes, it indeed is very tricky. For that there isn't real universal answer except socialism (as system which don't encourage nor require corruption) plus constant effort. Basically all socialist leaders wrote at least something about that. One of most notable examples is Xi Jinping, whose entire career is based on sucessful anticorruption activity on many levels of government.
What is human nature? If there is no obvious corruption then there can be hidden corruption. Socialist people could easily find each other and live together in harmony, but they don't, which suggests that some coercion is needed.
With effort, capitalism can be maintained, too. Elect a party that taxes capital and maintain the balance.
Would Xi Jinping be elected if there wasn't the threat of invasion and the existential need to avoid corruption?
If there is no obvious corruption then there can be hidden corruption.
Especially if you're imprisoned in the preemptive inquisitorial mindset which leads you to dismiss any potential change because it might not be perfect, which is sadly the case in a lot of western leftists.
Socialist people could easily find each other and live together in harmony, but they don’t, which suggests that some coercion is needed.
We all live in class societies and you can't just leave society, especially nowadays. And while you can try to chage it, by the means of revolution, there will be reaction. Recommended reading: Engels "The Origin of the Family, Private Property and the State", Marx "The Class Struggles in France, 1848 to 1850" and "The Civil War in France".
About coercion, what is needed first is the cessation of coercion and violence from capitalist states. So far, not happened anywhere, thus we need revolution.
With effort, capitalism can be maintained, too.
Not indefinitely. Capitalism require infinite growth but we only have finite planet. It is undoubtedly resilient system, as evidenced by its developing from ordinary capitalism into imperialism and then by several cycles inside the imperialism level, but eventually it will fall. Problem is, it will most likely kill all or most of us, destroy the planet and collapse entire civilisation. Thus we need to put a stop to it, the sooner the better.
Elect a party that taxes capital and maintain the balance.
As above, impossible. Again, Lenin's "Imperialism..." and Marx book 1 of "Capital". Last century is especially glaring example of complete failure of keynesian model, which wasn't even really fully implement anywhere.
Would Xi Jinping be elected if there wasn’t the threat of invasion and the existential need to avoid corruption?
Now that would be a magical world without any hardships. Sorry, marxism don't deal with that.
We MLs look to USSR, China, and the many smaller socialist countries such as Vietnam, Cuba etc. as examples of a preferable system.
The moment socialism is achieved in a country, all its standards of living skyrocket, by every metric. They often achieve rapid development, a boom of technological research, and a vast reduction in power of the personalities Keynes is referring to.
As Farvana above hints, the only reason this system hasn't rapidly become the standard worldwide is because of the powerful capitalist class greedily and violently protecting its power. Essentially almost every major conflict in the last century has ultimately been about the capitalist class, based in Western host nations, fighting to destroy socialism, the only thing that truly threatens their power.
Socialism is foundationally built on human cooperation. While there are many heart-warming examples of the peoples of these countries working fiercly together, both among themselves and with other countries oppressed by the West, they were born into a hostile world controlled by capitalism and have often had to emulate their enemies just to survive. China in the late 20th century used competition, among other capitalist mechanisms, in order to develop, integrate themselves into the world economy, and to appear obedient to the West so they could quietly build up enough power to act truly independently.
The reason the USSR collapsed is complicated but it really is just a matter of 8 decades of siege and the occasional foundational mistake all piling up and finally materializing in a capitalist coup of the socialist government that was wildly unpopular; it was THEN that lifestyle metrics sharply tanked. Socialism is the newest system in humanity, it has scarcely been around 100 years, it is experimental and the USSR was the first country of its kind. China carefully took notes and devised strategies to make sure they didn't suffer the same fate.
The rift part in my comment. I think it's not enough to blame the capitalist class. If the masses can be swayed by a few, whatever socialism is implemented can be toppled by a bad idea that happens to arise in somebody's mind.
If AES countries aren't a good enough example for you, then such a blueprint does not exist. I'm not sure why it would though. Was the ascendancy of capitalism over feudalism driven a meticulously detailed blueprint for the new world to come?
Competition? The "civilized" countries built their wealth through violent appropiation of other nations resources and enslavement of their people, not through "competition".