Despite the fears of international terrorist plots in the United States associated with Millennium celebrations, domestic special-interest or single-issue domestic terrorists committed 8 of the 10 terrorist incidents recorded in the United States during the calendar year; the remaining two incidents were perpetrated by rogue right-wing extremists. These 10 incidents doubled the number of terrorist incidents recorded the previous year. Six terrorist incidents in 1999 were attributed to an extremist movement known as the Animal Liberation Front (ALF). Combined, these attacks resulted in financial damages (primarily to medical research facilities) of more than three million dollars. Two acts of terrorism were attributed to a distinct but related movement known as the Earth Liberation Front (ELF). These attacks resulted in the complete destruction of an 8,000-square-foot office complex in Monmouth, Ore., and one million dollars in damage to the Agricultural Hall at Michigan State University. None of the incidents resulted in human casualties. For the sixth consecutive year, there were no successful acts of international terrorism perpetrated in the United States in 1999. An overview of international terrorism over the last three decades has been the most destructive in history. Over 14,000 international terrorist attacks have occurred worldwide since 1968. These attacks have resulted in more than 10,000 deaths. Between 1980 and 1999, the FBI recorded 327 incidents or suspected incidents of terrorism in the United States. Of these, 239 were attributed to domestic terrorists, and 88 were determined to be international. Combined, these acts resulted in the deaths of 205 persons and in the injury of over 2,037. Although the United States and the world now experience fewer acts of terrorism when compared to figures from the 1970's and 1980's, a troubling trend toward more destructive attacks has tempered this positive development. U.S. intelligence and law enforcement communities have developed an effective and highly integrated response to the challenge of terrorism. As the lead agency in the fight against terrorism in the United States, the highest priority of the FBI's Counterterrorism Program is to prevent acts of terrorism from occurring, but when acts do occur, the FBI mounts aggressive investigations to identify and apprehend the perpetrators. Increasingly, the FBI's efforts involve the assistance and cooperation of other intelligence and law enforcement agencies. Appendixes summarize terrorist incidents in the United States during the past decade and provide background information on currently designated foreign terrorist organizations and terrorist activities (1987-99), as well as a series of graphs that depict terrorist-related activity in the United States during the past two decades.