"A fifth column is a group of people who clandestinely undermine a larger group, such as a nation, from within. A fifth column can be a group of secret sympathizers of an enemy that are involved in sabotage within military defense lines, or a country's borders. A key tactic of the fifth column is the secret introduction of supporters into the whole fabric of the entity under attack. This clandestine infiltration is especially effective with positions concerning national policy and defense. From influential positions like these, fifth column tactics can be effectively utilized, from stoking fears through misinformation campaigns, to traditional techniques like espionage."