Supposedly, communism is created by Karl Marx to address the evils of capitalism (pursuit of profit at the expense of the "proletariat"). But is it fundamentally flawed?
Think about it: the idea that all properties are "shared" and belongs to the community/state is fine if you don't consider the following: someone must administer the whole thing. And doesn't that make the administrators the elite in this supposedly class-less society?
In other words, communism may work well enough in a small village, but if you go for large scale, the bureaucracy you must create to administer the realm is fundamentally opposed to the principle of "class-less" society. In other words, a "communist nation" is an oxymoron. You cannot be a nation, and be communist at the same time.