Different types of terrorism have been defined by lawmakers, security professionals and scholars. Types differ according to what kind of attack agents an attacker uses (biological, for example) or by what they are trying to defend (as in ecoterrorism).
Researchers in the United States began to distinguish different types of terrorism in the 1970s, following a decade in which both domestic and international groups flourished. By that point, modern groups had began to use techniques such as hijacking, bombing, diplomatic kidnapping and assassination to assert their demands and, for the first time, they appeared as real threats to Western democracies, in the view of politicians, law makers, law enforcement and researchers. They began to distinguish different types of terrorism as part of the larger effort to understand how to counter and deter it.
Many definitions of terrorism restrict it to acts by non-state actors.
But it can also be argued that states can, and have, been terrorists. States can use force or the threat of force, without declaring war, to terrorize citizens and achieve a political goal. Germany under Nazi rule has been described in this way.
It has also been argued that states participate in international terrorism, often by proxy. The United States considers Iran the most prolific sponsor of terrorism because Iran arms groups, such as Hizballah, that help carry out its foreign policy objectives. The United States has also been called terrorist, for example through its covert sponsorship of Nicaraguan Contras in the 1980s.
- Anthrax (Bacillus anthracis)
- Botulism (Clostridium botulinum toxin)
- The Plague (Yersinia pestis)
- Smallpox (Variola major)
- Tularemia (Francisella tularensis)
- Hemorrahagic fever, due to Ebola Virus or Marburg Virus
Narcoterrorism has had several meanings since its coining in 1983. It once denoted violence used by drug traffickers to influence governments or prevent government efforts to stop the drug trade. In the last several years, narcoterrorism has been used to indicate situations in which terrorist groups use drug trafficking to fund their other operations.