Of the Armenian massacres he wrote: "Democide had preceded the Young Turks' rule and with their collapse at the end of World War I, the successor Nationalist government carried out its own democide against the Greeks and remaining or returning Armenians.
Rummel -- who coined the term half a century ago -- has called democide (from the Greek "demos" meaning people), which is the murder of any people by their own government, including groups within the country that the leaders feel should be eradicated for political reasons, or due to perceived future threats.
The best to be said for Trevor-Roper the villain is that he probably did less harm than Trevor-Roper the dupe, who officially championed Anglo-Chinese friendship during Mao's democide, who spouted conspiracy theories about JFK's assassination, and who supplied (1983) his notorious endorsement of the so-called Hitler Diaries.
Table 1 compares war deaths and deaths resulting from democide, a term including genocide, politicide (targeted murder for political purposes), and mass murder (indiscriminate killing of any person or people).
Although the actual number of people killed by democide is virtually unknown, Rummel's books on the subject--Death by Government (1994) and Statistics of Democide (1997)--provide the most comprehensive estimates available.