He argued that taxation was theft on a grand scale, backed by law. It was "a compulsory monopoly of force" which prevented the more efficient voluntary procurement of defense and judicial services from competing suppliers. He also argued against central banking and fractional reserve banking. A monopoly system where the government decides how much money to print is, to him, a form of state-sponsored, legalized financial fraud. It is against libertarian principles and ethics. Rothbard opposed military, political, and economic interferences in the affairs of other nations.