The first article describes changes in terrorist organization, tactics, weaponry, sponsorship, training, mutual assistance and support, and operations and logistics since World War II. Counterterrorist tactics and legal and political sanctions for dealing with these changes also are discussed. Next, guidelines are presented for defusing hostage situations, with an emphasis on the role of the tactical response team and the hostage negotiator. The role of the emergency medical service system in dealing with casualties of terrorist actions is defined, and guidelines for integrating the system into the police contingency planning process are provided. Finally, the organization, responsibilities, training, and operations of GSG 9, a terrorist response division in the Federal Republic of Germany, are described.