Earth is a closed ecosystem. There is only so much oil, land, food, salt water, fresh water, cement, iron, and so on. Additionally, there are imbalances in access and distribution. Capitalism has an insatiable desire for "prosperity", which translates into wealth accumulation; in other words, unlimited, perpetual resource consumption. Ultimately, somebody somewhere will be left without a chair. When political and economic systems are designed to preserve the privileges of the "prosperous", what options are there other than violence?