Realist theories are self fulfilling prophecies, "people" are not generally greedy and evil, it is the norm of assuming this "fact" that perpetuates its relevance in the international system. While it's true that survival is a human instinct, I don't think anyone in their right mind would think we are simply creatures of instinct; at some point along the line we developed into empathetic and collaborative beings. The case for realism that essentially tries to translate "human nature" to the state and the international system is a fallacious argument. It sees a world of anarchy, and the state as an extension of the individual, so it treats all potential competitors as potential threats. The thing is, in any facet of society below that you would see that the majority of people do not generally kill each other simply because they are potential competitors; people as a whole cooperate with each other.

Of course rule of enforceable law is a partial reason for that, and anyone could also say that is an example of an extension of our cooperative nature, that is where the idea of liberalism comes in. The idea that you can regulate the states in the world with a system of laws and treaties like a state does with its population. With this comes the UN and its 200+ different missions focusing on different aspects of international law.

Zizek, a Marxist and Critical theorist simply takes these two arguments and says that none of the shit matters because we simple proletariat (worker class) are ruled by a bourgeoisie (business elite). A belief that all wars and all modern day government actions are just ways to ensure the status quo is maintained by and for the elite class. Marxism supports idea that suggests western societies are extensions of "elites" in a world and the developing world are what you would call the working class.

Basically, Communism is not Marxism, Socialism, or even Liberalism. Communism is the Utopian idea that people all rule themselves and government even in its most basic form is non existent - and would have no need to be existent. It was supported by Marx as the only way for humanity to truly be free from war and oppression. There would be no currency and no need for it because all items sustainable for life would be distributed equally throughout society. The idea is that people could focus on the finer things in life as a result of this freedom from the urge to overcome others. With that said, "communism has never existed", all governments claiming to be communist were actually socialist (ie. Russia, China, Vietnam, Cuba.)

Socialism is a necessary step to becoming communist according to Marx, but the problem has always lied in moving from socialism to communism because the ones who attempted to inadvertently set up an elite system themselves. The reason Soviet Union sent all their dissidents and intellectuals to Siberia was because the Soviet Union was trying to rid themselves of the capitalist impulses in order to set up a truly communist system. They inadvertently set up their own "elite" classes of government and military officials by doing this though, which actually made the government of the Soviet Union more evil according to Marx theory than everyday capitalism.

Constructivism is the "Matrix" theory of world politics, and I think this is the most relevant. This theory states that all social reality is constructed, and the foundational theories of Realism and Liberalism are just constructed norms. People aren't really evil, but if it is generally believed to be so, then people will approach the world as if it is, and will continuously ensure that it always will be. In the case of Liberalism this is quite obvious, cooperation and laws are obviously constructed. How else would it be that negative connotation of the concept of "genocide" is only a recent occurrence? The Vikings, the Mongols, the Romans, and even the bloody Jews in the Bible habitually killed whole towns when they passed through and it was just considered a part of war. Only when a word was attributed to this, have politician even considered the moral implications of it. So to a Constructivist, whichever people are in power and what their dialogue is, is the prime determinate of the nature of a state. Thus far, it's the only theory that accounts for the fact that humans are creative and dynamic beings that can and do construct their own realities.

So there we have it folks, these are the main theories that define world politics (not mentioning feminism and environmentalism). I think the only right phrase for it is "complex as fuck", but when you start to be able to switch through these lenses and identify exactly where these talking head's ideas are derived from, then you basically have everything you need to know what the hell is going on in the world. The truth is, all this thinking is going on simultaneously in the heads of many international policymakers, so its very fucking difficult to really have a firm understanding of what is going on around the world. The one thing you can be certain of though, is how narrow-minded a person has to be to ascribe themselves to realism in its totality. Realism sounds pretty brilliant on the surface, I mean, it does seem like everyone is just looking out for their own self interest, even in the oh so popular European stance of criticizing America. But having this as the end all argument in my opinion is the dumbest, most narrow minded approach anyone can take.

TLDR// What I came here to say is Horowitz a dipshit obviously, but what he is saying comes from an actual well developed school of thought called realism. It is the dominate stance of most American politics and military thought. With that said, this school of thought in itself is stupid, and he is stupid for defending a stone-aged theory and not know the difference between Communism, Liberalism, Socialism, and Marxism.