In "", Jacques Ellul discusses psychological warfare as a common peace policy practice between nations as a form of indirect aggression. This type of propaganda drains the public opinion of an opposing regime by stripping away its power on public opinion. This form of aggression is hard to defend against because no international court of justice is capable of protecting against psychological aggression since it cannot be legally adjudicated. "Here the propagandists is dealing with a foreign adversary whose morale he seeks to destroy by psychological means so that the opponent begins to doubt the validity of his beliefs and actions."There is evidence of psychological warfare throughout written history. In modern times, psychological warfare efforts have been used extensively. Mass communication allows for direct communication with an enemy populace, and therefore has been used in many efforts. In recent times, social media channels and the internet allow for campaigns of disinformation and misinformation performed by agents anywhere in the world.