The answer is blatantly obvious to me but I'll spell it out anyway. Power. The world used to run on slavery, and in many places still does. Western Civilization has thrived on the Judeo-Christian concept of individual responsibility - distribution of power (as in autonomy) as widely as possible. People making their own decisions and being responsible for the outcome of those decisions, good or bad. Think about it. True freedom is being able to make a choice and reap the rewards or penalty of that choice. Contrast that with systems where all the power is sucked upwards into a cabal, or leadership oligarchy or simply a dictator. That's intoxicating if you are that leader. Kim Jong Il has the intoxicating ability to control every single one of NK's 25 million inhabitants, even controlling their emotions. The Left believe in a utopian vision where an establishment elite can make all the important decisions for the whole world. Standing in the way are people who want to make their own decisions where and how they live. Those people can be crushed by the government if they are tagged as insurrectionists rather than dissenters.