There are no "paradoxes" of quantum mechanics. QM is a perfectly internally consistent theory. Most so-called "paradoxes" are just caused by people not understanding it.

QM is both probabilistic and, in its own and very unique way, relative. Probability on its own isn't confusing, if the world was just fundamentally random you could still describe it in the language of classical probability theory and it wouldn't be that difficult. If it was just relative, it can still be a bit of a mind-bender like special relativity with its own faux paradoxes (like the twin "paradox") that people struggle with, but ultimately people digest it and move on.

But QM is probabilistic and relative, and for most people this becomes very confusing, because it means a particle can take on a physical value in one perspective while not having taken on a physical value in another (called the relativity of facts in the literature), and not only that, but because it's fundamentally random, if you apply a transformation to try to mathematically place yourself in another perspective, you don't get definite values but only probabilistic ones, albeit not in a superposition of states.

For example, the famous "Wigner's friend paradox" claims there is a "paradox" because you can setup an experiment whereby Wigner's friend would assign a particle a real physical value whereas Wigner would be unable to from his perspective and would have to assign an entangled superposition of states to both his friend and the particle taken together, which has no clear physical meaning.

However, what the supposed "paradox" misses is that it's not paradoxical at all, it's just relative. Wigner can apply a transformation in Hilbert space to compute the perspective of his friend, and what he would get out of that is a description of the particle that is probabilistic but not in a superposition of states. It's still random because nature is fundamentally random so he cannot predict what his friend would see with absolute certainty, but he can predict it probabilistically, and since this probability is not a superposition of states, what's called a maximally mixed state, this is basically a classical probability distribution.

But you only get those classical distributions after applying the transformation to the correct perspective where such a distribution is to be found, i.e. what the mathematics of the theory literally implies is that only under some perspectives (defined in terms of any physical system at all, kind of like a frame of reference, nothing to do with human observers) are the physical properties of the system actually realized, while under some other perspectives, the properties just aren't physically there.

The Schrodinger's cat "paradox" is another example of a faux paradox. People repeat it as if it is meant to explain how "weird" QM is, but when Schrodinger put it forward in his paper "The Present Situation in Quantum Mechanics," he was using it to mock the idea of particles literally being in two states at once, by pointing out that if you believe this, then a chain reaction caused by that particle would force you to conclude cats can be in two states at once, which, to him, was obviously silly.

If the properties of particles only exist in some perspectives and aren't absolute, then a particle can't meaningfully have "individuality," that is to say, you can't define it in complete isolation. In his book "Science and Humanism," Schrodinger talks about how, in classical theory, we like to imagine particles as having their own individual existence, moving around from interaction to interaction, carrying their properties with themselves at all times. But, as Schrodinger points out, you cannot actually empirically verify this.

If you believe particles have continued existence in between interactions, this is only possible if the existence of their properties are not relative so they can be meaningfully considered to continue to exist even when entirely isolated. Yet, if they are isolated, then by definition, they are not interacting with anything, including a measuring device, so you can never actually empirically verify they have a kind of autonomous individual existence.

Schrodinger pointed out that many of the paradoxes in QM carry over from this Newtonian way of thinking, that particles move through space with their own individual properties like billiard balls flying around. If this were to be the case, then it should be possible to assign a complete "history" to the particle, that is to say, what its individual properties are at all moments in time without any gaps, yet, as he points out in that book, any attempt to fill in the "gaps" leads to contradiction.

One of these contradictions is the famous "delayed choice" paradox, whereby if you imagine what the particle is doing "in flight" when you change your measurement settings, you have to conclude the particle somehow went back in time to rewrite the past to change what it is doing. However, if we apply Schrodinger's perspective, this is not a genuine "paradox" but just a flaw of actually interpreting the particle as having a Newtonian-style autonomous existence, of having "individuality" as he called it.

He also points out in that book that when he originally developed the Schrodinger equation, the purpose was precisely to "fill in the gaps," but he realized later that interpreting the evolution of the wave function according to the Schrodinger equation as a literal physical description of what's going on is a mistake, because all you are doing is pushing the "gap" from those that exist between interactions in general to those that exist between measurement, and he saw no reason as to why "measurement" should play an important role in the theory.

Given that it is possible to make all the same predictions without using the wave function (using a mathematical formalism called matrix mechanics), you don't have to reify the wave function because it's just a result of an arbitrarily chosen mathematical formalism, and so Schrodinger cautioned against reifying it, because it leads directly to the measurement problem.

The EPR "paradox" is a metaphysical "paradox." We know for certain QM is empirically local due to the no-communication theorem, which proves that no interaction a particle could undergo could ever cause an observable alteration on its entangled pair. Hence, if there is any nonlocality, it must be invisible to us, i.e. entirely metaphysical and not physical. The EPR paper reaches the "paradox" through a metaphysical criterion it states very clearly on the first page, which is to equate the ontology of a system to its eigenstates (to "certainty"). This makes it seem like the theory is nonlocal because entangled particles are not in eigenstates, but if you measure one, both are suddenly in eigenstates, which makes it seem like they both undergo an ontological transition simultaneously, transforming from not having a physical state to having one at the same time, regardless of distance.

However, if particles only have properties relative to what they are physically interacting with, from that perspective, then ontology should be assigned to interaction, not to eigenstates. Indeed, assigning it to "certainty" as the EPR paper claims is a bit strange. If I flip a coin, even if I can predict the outcome with absolute certainty by knowing all of its initial conditions, that doesn't mean the outcome actually already exists in physical reality. To exist in physical reality, the outcome must actually happen, i.e. the coin must actually land. Just because I can predict the particle's state at a distance if I were to travel there and interact with it doesn't mean it actually has a physical state from my perspective.

I would recommend checking out this paper here which shows how a relative ontology avoids the "paradox" in EPR. I also wrote my own blog post here which if you go to the second half it shows some tables which walk through how the ontology differs between EPR and a relational ontology and how the former is clearly nonlocal while the latter is clearly local.

Some people frame Bell's theorem as a paradox that proves some sort of "nonlocality," but if you understand the mathematics it's clear that Bell's theorem only implies nonlocality for hidden variable theories. QM isn't a hidden variable theory. It's only a difficulty that arises in alternative theories like pilot wave theory, which due to their nonlocal nature have to come up with a new theory of spacetime because they aren't compatible with special relativity due to the speed of light limit. However, QM on its own, without hidden variables, is indeed compatible with special relativity, which forms the foundations of quantum field theory. This isn't just my opinion, if you go read Bell's own paper himself where he introduces the theorem, he is blatantly clear in the conclusion, in simple English language, that it only implies nonlocality for hidden variable theories, not for orthodox QM.

Some "paradoxes" just are much more difficult to catch because they are misunderstandings of the mathematics which can get hairy at times. The famous Frauchiger–Renner "paradox" for example stems from incorrect reasoning across incompatible bases, a very subtle point lost in all the math. The Cheshire cat "paradox" tries to show particles can disassociate from their properties, but those properties only "disassociate" across different experiments, meaning in no singular experiment are they observed to dissociate.

I ran out of charact-

(1) Marxists are pro-centralization, not decentralization. We're not anarchists/libertarians. This is good for us as it lays the foundations for socialist society, while also increasing the contradictions within capitalist society, bringing the socialist revolution closer to fruition.

This centralist tendency of capitalistic development is one of the main bases of the future socialist system, because through the highest concentration of production and exchange, the ground is prepared for a socialized economy conducted on a world-wide scale according to a uniform plan. On the other hand, only through consolidating and centralizing both the state power and the working class as a militant force does it eventually become possible for the proletariat to grasp the state power in order to introduce the dictatorship of the proletariat, a socialist revolution.

Rosa Luxemburg, On the National Question

Communist society is stateless. But if true - and most certainly it is - what really is the difference between anarchists and Marxist communists? Does this difference no longer exist, at least on the question of the future society and the "ultimate goal"? Of course it exists, but is altogether different. It can be briefly defined as the difference between large centralized production and small decentralized production. We communists on the other hand believe that the future society...is large-scale centralized, organized and planned production, tending towards the organization of the entire world economy...Future society will not be born of "nothing", will not be delivered from the sky by a stork. It grows within the old world and the relationships created by the giant machinery of financial capital. It is clear that the future development of productive forces (any future society is only viable and possible if it develops the productive forces of the already outdated society) can only be achieved by continuing the tendency towards the centralization of the production process, and the improved organization of the "direction of things" replacing the former "direction of men".

Nikolai Bukharin, Anarchy and Scientific Communism

The advance of industry, whose involuntary promoter is the bourgeoisie, replaces the isolation of the labourers, due to competition, by the revolutionary combination, due to association. The development of Modern Industry, therefore, cuts from under its feet the very foundation on which the bourgeoisie produces and appropriates products. What the bourgeoisie therefore produces, above all, are its own grave-diggers.

Marx & Engels, Manifesto of the Communist Party

(2) Much of your discussion just regards how AI is turning artists into an "extension of the machine" and further alienating their labor. But, like, that's already true for most workers. Petty bourgeois artists will have to fall to the low, low place of the common working man... gasp! The reality is that it is good for us, because a lot of these petty bourgeois artists, precisely because they are "self-made" and not as alienated from their labor as regular workers, tend to have more positive views of property right laws. If more of them become "extensions of the machine" like every proles, then their interests will become more materially aligned with the proles. They would stop seeing art as a superior kind of labor that makes them better and more important than other workers, but would see themselves as equal with the working class and having interests aligned with them.

(3) Your discussion regarding Deepseek is confusing. Yes, the point of AI is to improve productivity, but this is an objectively positive thing and the driving force of history that all Marxists should support. The whole point of revolution is that the previous system becomes a fetter on improving productivity. Whether or not Deepseek was created to improve productivity for capitalist or socialist reasons, either way, improving productivity is a positive thing. It is good to reduce labor costs.

[I]t is only possible to achieve real liberation in the real world and by employing real means, that slavery cannot be abolished without the steam-engine and the mule and spinning-jenny, serfdom cannot be abolished without improved agriculture, and that, in general, people cannot be liberated as long as they are unable to obtain food and drink, housing and clothing in adequate quality and quantity. “Liberation” is an historical and not a mental act, and it is brought about by historical conditions, the development of industry, commerce, agriculture, the conditions of intercourse.

Marx, Critique of the German Ideology

The proletariat will use its political supremacy to wrest, by degrees, all capital from the bourgeoisie, to centralise all instruments of production in the hands of the State, i.e., of the proletariat organised as the ruling class; and to increase the total of productive forces as rapidly as possible.

Marx & Engels, Manifesto of the Communist Party

(4) Clearly, for the proletariat, we "full proletarianization of the arts" is by definition a good thing for the proletarian movement.

You people have good luck with this? I haven't. I don't find that you can just "trick" people into believing in socialism by changing the words. The moment if becomes obvious you're criticizing free markets and the rich and advocating public ownership they will catch on.

Trump flubbed the "peace talks" with the DPRK so I don't know why people trust him to do it correctly with Russia. Trump also is a major reason for the war because Putin was hoping to be able to negotiate with the Trump administration the first time around but all Trump did the first time around was ramp up sanction on Russia. After Trump left office they gave up negotiations.

Marxism is supposed to be a scientific theory of development. The point of the proletariat seizing power and nationalizing industry is to resolve the contradiction between the socialization of labor/production, which results from the development of big industry which drags capitalists against their will from complete isolation to complete socialization, and private appropriation. Due to private ownership, a small number of people control the appropriation of resources, but as enterprises get larger and larger, more and more people work together collectively to produce those resources.

This contradiction increases as larger enterprises get until eventually it is no longer sustainable and starts becoming socially unstable and hindrance to further development. The proletariat seizing state power and nationalizing these big industries replaces private appropriation with socialized appropriation and thus resolves the contradiction as it is consistent with socialized production/labor.

The reason I tell you all this is because people often misunderstand Marxism as just "private property = bad," and if you believe "private property = bad," then from that standpoint you would want to abolish it immediately under any conditions. But that's not Marxism, in Marxism, the nationalization of industry is for very specific economic reasons, and so by necessity those conditions must first exist to justify nationalizing industry. And what are those conditions? Heavily socialized production/labor which is a result of the development of big industry.

Hence, you need big industry first in order to justify nationalizing, or else you've abandoned historical materialism for moralism. This is why the Manifesto does not call for the immediate abolition of all private property, but in the program Marx suggests he only calls for an immediate extension of industry owned by the state, and then says the rest can come gradually, "by degrees," alongside developing the forces of production as rapidly as possible.

Why is developing the forces of production important? Because by doing so you encourage more sectors of the economy to develop into big enterprises. If you read The Principles of Communism Engels says clearly that big enterprises can only develop in a competitive market economy, and therefore you cannot abolish private property in one stroke because you have to let the forces of production develop which can take a long time.

This is also why Marx believed you needed the dictatorship of the proletariat. It makes no sense to speak of a state without classes as he viewed the state as a tool of class oppression. He says clearly in Conspectus of Bakunin’s Statism and Anarchy that class distinctions will still exist because the economic conditions that give rise to non-proletarian classes (the decentralization of production due to underdevelopment) would not immediately go away and would likely not go away for a long time.

Lenin understood this too, he warned against the nationalization of small producers multiple times. In The Tax in Kind he says that it would be economic suicide to nationalize the small producers, and in Left-wing Communism: An Infantile Disorder he says that the proletarian state just needs to "learn to live with them" (the small producers). There is just no reading of Marx that gets around the fact that if we take Marxian political economy seriously then the nationalize of enterprises is only applicable to big industry. It is just not applicable at all to small industry.

Mao did start off rather materialist and some of his earlier works are pretty good, but over time as he got old he seemed to move more towards moralism and tried to rapidly nationalize everything even though it made little economic sense. When it was leading to economic difficulties, he thought the problem was bad influences of bourgeois morality and a cultural revolution would help purge those bourgeois moral elements from the superstructure. However, this just led to a practical civil war and was a complete disaster.

When Mao died, the Gang of Four made it clear they had completely abandoned any pretense of being materialist and had just become pure moralists, outright saying that they would prefer China to be poor than to ever allow an inch of private enterprise to operate in the country. The situation was so dire that Hua Guofeng, Mao's own chosen successor, had the Gang of Four arrested. Mao had so many great achievements I don't really like talking much about his failures but this was all a disaster but luckily his successor managed to fix it.

However, "Maoists" think the older Mao's policies were all actually a good thing, that the problem really was moral bourgeois corruption in the superstructure and the only reason his policies failed because he didn't implement them early enough. Maoists insist that any socialist country that actually follows the Marxian path of development has betrayed "true socialism" as "true socialism" according to them would nationalize everything and if there is one iota from private enterprise in your country then you are an evil immoral revisionist capitalist roader.

Materialist dialectics rejects that any definition we come up with to describe something will ever accurately capture it as it exists in the real world, because everything contains internal contradictions and only exists in its interrelations with everything else. In a sense, definitions are all abstractions which only approximate reality, and so we instead define things based on their dominant characteristics. There will never be a society that fits the definition of capitalism or socialism perfectly, so we instead focus on what are the dominant characteristics (principle aspects) of that society.

As Mao explained, whatever is the principle aspect will shape everything else, it will shape all contradictory aspects and those contradictory aspects will take on characteristics of the principle aspect. Take public property for example. Most capitalist states have public property on paper, but does that mean they are socialist? No, because in a state overwhelmingly dominated by private capital, capital owners will control the state, and thus the public sector will ultimately exist at the behest of private interests and will take on a private character.

On the other hand, consider a society that is dominated by public ownership but contains a single private enterprise. That private enterprise will have to acquire its land and all its resources to produce its product from the public sector, and then when it sells its product, it would be selling to workers of the public sector, ultimately selling to public enterprise. So, the public sector would control all of its inputs and outputs, its supply and demand, and thus the private enterprise would effectively be under the control of the public sector and would therefore take on a public character. Hence, such a contradictory aspect within a socialist society would not be sufficient reason to say it is not socialist.

Hence, what makes state capitalism state capitalism is when capital owners nationalize industries but the capitalist class still remains in control of the state, and thus they are operated within the framework of the interests of capital and profits and still retain their capitalistic character.

Liberal society likes to separate things into the "private sector" and "the government/state sector" when in reality private enterprise are forms of local governance that are recognized and defended by the state, and thus are ultimately part of the state and not separate from it. A more coherent analysis would be to separate society into the autocratic and the democratic sector, as this is more close to what is meant when Marxists talk about public vs private property.

To own something means to have a say in its use, and so for a sector to be genuinely public it must be democratic, the working masses have to have input. Nationalization thus does not necessarily mean the transfer from private to public property. The state can still operate property privately. Even if the state nationalizes everything, it is still capitalism if it is still operated at the behest of private interests and not for the masses. When I think state capitalism I think of something like Saudi Arabia where much of the economy is owned by the state but the royal family is recognized as the private owners and they don't even pretend that the working masses have any say. Or I think of modern Russia where on paper they have significant public ownership over the economy but the country is clearly controlled by private oligarchs and so these aren't being put in service of the people; social services are crumbling.

Also, Maoists are pure moralists, don't pay them much attention.

What makes a social media platform good is, well, socializing, so people are naturally going to flock to where the most people already are. I am only here because I am blocked from r*ddit.

I don't really agree. US propaganda is absurdly effective and for some reason no other country has been capable of replicating it. I think the problem is socialist countries tend to be too honest. Their propaganda against western countries is often to just tell it like it is. A lot of people in the USSR doubted it and genuinely believed the USA was a utopia and the Soviet propaganda was just all lies, and so that's why many supported Yeltsin. You see the same with China today, if you ask Chinese opinion on the USA you will be surprised that most don't see the USA a dystopia but as a utopia. Many Chinese people have frequently told me they thought in the USA people only work four days a week and health care is free.

US propaganda is much more effective because they just make absurdly extreme lies, claiming that socialist countries are all literally hell on earth. The reason this is so effective because most reasonable people who recognize their state is probably going to lie to them for their own benefit are also afraid of becoming dogmatic in the opposite direction, and so they falsely assume that "the truth must be somewhere in the middle." In other words, if the state says a country like the former USSR was literally hell on earth where everyone starved, the "reasonable" person isn't just going to assume that the USSR wasn't literally hell on earth, because they have a cognitive bias that makes them not want to come across as too dogmatic in the opposite direction, so they will instead conclude that he USSR was slightly hell on earth.

You see this tactic used all the time in liberal media. They always exaggerate things to the most ridiculous degree, like in the DPRK they publicly execute you with artillery for having the wrong haircut or feed you to dogs. This propaganda is so effective because even people who recognize this propaganda is indeed propaganda will still buy into it somewhat, and so the lie still works on them. An obvious example is the "100 million dead" claim which we all know is just a completely fabricated number, but even more "reasonable" people who recognize it is fabricated just assumes the number is less but still in the tens of millions, so they still have bought into the propagandistic framing that it even makes sense to blame socialism/communism for these kinds of deaths at all. They already buy into a framework which is biased against socialism/communism because they'll never apply this same kind of arbitrary body count analysis to capitalism, and so they're already successfully propagandized by assuming their is some truth to it even if they admit the 100 million number is exaggerated propaganda.

This tactic was first introduced by Adolf Hitler when had talked about what he called the "Big Lie" in Mein Kampf, explaining it as a propaganda tool the Nazis would use where they would make lies so extraordinarily exaggerated that most people assume there must be at least some truth to them, even if they don't buy into it completely. But if you buy into it at all, you have already fallen for the lie, and so you are already successfully propagandized.

Western countries really have their propaganda down to a science and no one can compete. Chinese people do not have some sort of magical mental barrier that can block out all western propaganda, they are human beings just like all of us and are susceptible to the same kind of propaganda, and I fear it would have far more negative impact than positive to let a flood of western propaganda into China. I mean, this was already kind of attempted at a small scale in Hong Kong and we saw how that turned out.

Maybe. In one Chinese textbook I read, the author routinely criticized the USSR's policies in the way it enforced socialism in other countries, usually enforcing a vision of socialism of specifically Russian origin and oppressing local socialist movements who wanted to tailor socialism to their own material conditions. The Chinese did not like this kind of domination and were fearful of it because they did not want to become a Soviet puppet. I think the Soviets could have potentially made decisions to show it was less interested in domination, but I also do think it is fair to say the Chinese could have been less paranoid as well. It's hard for me to specifically pick a side because both Mao and Khrushchev did/said some unhinged things at times.

To put it as simply as possible, in quantum mechanics, the outcome of events is random, but unlike classical probability theory, you can express probabilities as complex numbers. For example, it makes sense in quantum mechanics to say an event has a -70.7i% chance of occurring. This is bit cumbersome to explain, but the purpose of this is that there is a relationship between [the relative orientation between the measurement settings and the physical system being measured] and [the probability of measuring a particular outcome]. Using complex numbers gives you the additional degrees of freedom needed to represent both of these things simulateously and thus relate them together.

In classical probability theory, since probabilities are only between 0% and 100%, they can only accumulate, while the fact probabilities in quantum mechanics can be negative allows for them to cancel each other out. You can have the likelihood of one event not add onto another, but if it is negative, basically subtract from it, giving you a total chance of 0% of it occurring. This is known as destructive interference and is pretty much the hallmark effect of quantum mechanics. Even entanglement is really just interference between statistically correlated systems.

If you have seen the double-slit experiment, the particle has some probability of going through one slit or the other, and depending on which slit it goes through, it will have some probability of landing somewhere on the screen. You can compute these two possible paths separately and get two separate probability distributions for where it will land on the screen, which would look like two blobs of possible locations. However, since you do not know which slit it will pass through, to compute the final distribution you need to overlap those two probability distributions, effectively adding the two blobs together. What you find is that some parts of the two distributions cancel each other out, leaving a 0% chance that the particle will land there, which is why there are dark bands that show up in the screen, what is referred to as the interference pattern.

Complex-valued probabilities are so strange that some physicists have speculated that maybe there is an issue with the theory. The physicist David Bohm for example had the idea of separating the complex numbers into their real and imaginary parts, and just using two separate real functions. When he did that, he found he could replace the complex-valued probabilities with real-valued probabilities alongside a propagating "pilot wave," kinda like a field.

However, the physicist John Bell later showed that if you do this, then the only way to reproduce the predictions of quantum mechanics would be to violate the speed of light limit. This "pilot wave" field would not be compatible with other known laws of physics, specifically special relativity. Indeed, he would publish a theorem that proves that any attempt to get rid of these weird canceling probabilities and replacing them with more classical probabilities ends up breaking other known laws of physics.

That's precisely where "entanglement" comes into the picture. Entanglement is just a fancy word for a statistically correlated system. But the statistics of correlated systems, when you have complex-valued probabilities, can make different predictions than when you have only real-valued probabilities, it can lead to certain cancellations that you would not expect otherwise. What Bell proved is that these cancellations in an entangled system could only be reproduced with a classical probability theory if it violated the speed of light limit. Despite common misconception, Bell did not prove there is anything superluminal in quantum mechanics, only that you cannot replace quantum mechanics with a classical-esque theory without it violating the speed of light limit.

Despite the fact that there are no speed of light violations in quantum mechanics, these interference effects have results that are similar to that if you could violate the speed of light limit. This ultimately allows you to have more efficient processing of information and information exchange throughout the system.

A simple example of this is the quantum superdense coding. Let's say I want to send a person a two-qubit message (a qubit is like a bit, either 0 or 1), but I don't know what the message is, but I send him a single qubit now anyways. Then, a year later, I decide what the message should be, so I send him another qubit. Interestingly enough, it is in principle to setup a situation whereby the recipient, who now has two qubits, could receive both qubits you intend to send across those two qubits they possess, despite the fact you transmitted one of those long before you even decided what you wanted the message to be.

It's important to understand that this is not because qubits can actually carry more than one bit of information. No one has ever observed a qubit that was not either a 0 or 1. It cannot be both simulateously nor hold any additional information beyond 0 or 1. It is purely a result of the strange cancellation effects of the probabilities, that the likelihoods of different events occurring cancel out in a way that is very different from your everyday intuition, and you can make clever use of it to cause information to be (locally) exchanged throughout a system more efficiently than should be possible in classical probability theory.

There is another fun example that is known as the CHSH game. The game is simple, each team is composed of two members who at the start of the round are each given a card with randomly the numbers 0 or 1. The number on the card given to the first team member we can call X and the number of the card given to the second team member we can call Y. The objective of the game is for the two team members to then turn over their card and write their own 0 or 1 on the back, which we can call what they both write on their cards A and B. When the host collects the cards, he computes X and Y = A xor B, and if the equality holds true, the team scores a point.

The only kicker is that the team members are not allowed to talk to one another, they have to come up with their strategy beforehand. I would challenge you to write out a table and try to think of a strategy that will always work. You will find that it is impossible to score a point better than 75% of the time if the team members cannot communicate, but if they can, you can score a point 100% of the time. If the team members were given statistically correlated qubits at the beginning of the round and disallowed from communicating, they could actually make use of interference effects to score a point ~85% of the time. They can perform better than should be physically possible in a classical probability theory without being able to communicate despite the fact they are not communicating. The No-communication Theorem proves that there is no communication between entangled qubits, these effects come from interference.

While you can build a quantum computer using electron spin as you mentioned, it doesn't have to be. There are many different technologies that operate differently. All that you need is something which can exhibit these quantum interference effects, something that can only be accurately predicted using these complex-valued probabilities. Electron spin is what people often first think of because it is simple to comprehend. Electrons can only have two spin values of up or down, which you can map to 0 and 1, and you can directly measure it using a Stern-Garlach apparatus. This just makes electron spin simple as a way to explain how quantum computing works to people, but they definitely do not all operate on electron spin. Some operate on photon polarization for example. Some operate on the motion of Ytterbium ions trapped in an electromagnetic field.

It's kind of like how you can implement bits using different voltage levels where 0v = 0 or 3.3v = 1, or how you can implement bits using the direction of magnetic polarization on a spinning platter in a hard drive whereby polarization in one direction = 0 and polarization in the opposite direction = 1. There are many different ways of physically implementing a bit. Similarly, there are many different ways of implementing a qubit. It also needs at minimum two discrete states to assign to 0 or 1, but on top of this it needs to follow the rules of quantum probability theory and not classical probability theory.

Historically the US would go to war or even coup countries to force them to trade with the US, it has spent a very long time building up its dollar hegemony. If it suddenly switches to cutting off trade with its largest trading partners, that will basically disappear overnight. It is already disappearing gradually because of US's obsessive use of sanctions has created a whole bloc of countries that have no choice but to figure out how to bypass the US dollar. I wouldn't even consider the US threatening to cut trade ties all its largest trading partners as "bullying," it really reflects how much weaker the US has become, because in the past it would just use force to enforce its hegemony over global trade, now it seems too weak to it is just threatening to throw a temper tantrum and threatening to pull out of the global market instead, despite this being something that will ultimately cause whatever is left of US hegemony to collapse overnight. I would bet a lot of money the US would not actually do this, Trump is just bluffing, because I'm sure he's surrounded by people who actually do care about maintaining US control.