Internationally terrorism has fluctuated markedly from year to year. For example, terrorist events in Italy increased from under 400 per year in 1969-1970 to over 2000 in 1978-1979 and fell to less than 100 in the mid 1980s. In Canada, terrorist events averaged more than 40 per year from 1968-1971 before declining through the late 1970s. A similar peak in political terrorism in the late 1960s in the United States was followed by a decline, from about 120 events annually in the mid 1970s to 12 events per year in 1984-1986. The declining incidence of terrorism by domestic opposition groups such as the Quebec separatists and Doukhobors in Canada and right-wing extremist groups in the United States is documented and examined in detail in this comparative study of political terrorism. In both countries, the decline can be attributed somewhat to partial resolution of the issues in the political arena. 4 tables, 48 notes.