A governmental “intervention” is a law or action which changes what people would otherwise voluntarily do. Interventions are market-hampering, as the use of force by government reduces the well-being of the people who are coerced. In contrast, laws which protect property rights are market-enhancing, as they increase the well-being of people; such laws are not interventions.

The word “intervene” derives from the Latin words “inter,” between, and “venire” to come. To “intervene” means to come between two or more things, to interfere in order to change the outcome. If a US company seeks to export goods to Cuba, and the government prohibits this trade, the government comes between the parties that sought to trade, changing the outcome to not trading.

To analyze intervention, we first need to understand its absence, liberty. In a purely free society, the law prohibits only acts which coercively harm others. A harm is an invasion…