State terrorism
While the most common modern usage of the word terrorism refers to civilian-victimising political violence by insurgents or conspirators, several scholars make a broader interpretation of the nature of terrorism that encompasses the concepts of state terrorism and state-sponsored terrorism. Michael Stohl argues, "The use of terror tactics is common in international relations and the state has been and remains a more likely employer of terrorism within the international system than insurgents. Stohl clarifies, however, that "[n]ot all acts of state violence are terrorism. It is important to understand that in terrorism the violence threatened or perpetrated, has purposes broader than simple physical harm to a victim. The audience of the act or threat of violence is more important than the immediate victim."
Terrorism
The perpetrators of acts of terrorism can be individuals, groups, or states. According to some definitions, clandestine or semi-clandestine state actors may also carry out terrorist acts outside the framework of a state of war. However, the most common image of terrorism is that it is carried out by small and secretive cells, highly motivated to serve a particular cause and many of the most deadly operations in recent times, such as the September 11 attacks, the London underground bombing, 2008 Mumbai attacks and the 2002 Bali bombing were planned and carried out by a close clique, composed of close friends, family members and other strong social networks. These groups benefited from the free flow of information and efficient telecommunications to succeed where others had failed.