Hiwet Teklu’s son Samson was 22 years old in 1978 when he was arrested by agents of the Ethiopian government. He was tortured for 15 days and then shot. His mother found his lifeless body on her front doorstep the next morning. At least she was spared the indignity of the “wasted bullet” tax, which relatives of the victims of the Ethiopian “Red Terror” usually had to pay to the government in order to have the bodies released for burial.

Samson was a member of an opposition student movement — a crime in Ethiopia under the rule of a Marxist military dictator named Mengistu Haile Mariam. Samson was only one of many thousands of his countrymen who lost their lives during the Red Terror, which lasted from 1974 to 1991. Yet most people have forgotten that Mengistu is still living in exile in Zimbabwe. As the situation in Zimbabwe deteriorates, we should remember that Robert Mugabe is not the only dictator whose future hangs in the balance. If Mugabe falls, Mengistu should also face justice.

Mengistu Haile Mariam was born in 1937. He joined the army at an early age and by 1974, when the military overthrew Emperor Haile Selassie, was a major. He thus became a member of the military junta known as the Derg. Mengistu soon distinguished himself by both his radicalism and ruthlessness. Having executed Gen. Teferi Benti, the Derg’s chairman, Mengistu succeeded him in 1977.

The next 14 years in Ethiopia were marked by the typical Marxist trifecta: murder, economic collapse and famine. First, Mengistu turned on his opponents from the Ethiopian People’s Revolutionary Party and All-Ethiopia Socialist Movement. In the violence that followed, tens of thousands of people lost their lives. Some of them were mere children. According to a report issued by the Swedish Save the Children Fund in May 1977, for example, “1,000 children have been killed, and their bodies are left in the streets and are being eaten by wild hyenas…You can see the heaped-up bodies of murdered children, most of them aged 11 to 13, lying in the gutter, as you drive out of Addis Ababa.”

Second, Mengistu embraced the disastrous economics of central planning. All private businesses, such as banks and factories, were nationalized and put under the control of Soviet-style bureaucracies. The Derg shut down Ethiopia’s schools and universities for two years, forcing the students to move to the countryside to implement land nationalization. Land nationalization exacerbated the effects of the drought, severely reducing the output of Ethiopian farmers. By 1984, Ethiopia was suffering a full-blown famine.

Mengistu initially denied that the famine existed. Instead, he devoted much of the state’s resources to celebrating the 10th anniversary of the Derg’s rise to power. Soon, however, Mengistu realized that he could use the world’s sympathy to his advantage. As images of Ethiopian babies with kwashiorkor bellies beamed into Western living rooms, foreign aid and food poured into the country. Private charities raised money, too, as did the first Live Aid concert organized by Bob Geldof.

Unbeknownst to many people, the Derg channeled some of the aid to feed the military machine in its war against two rebel movements: the Ethiopian Peoples’ Revolutionary Democratic Front and Eritrean People’s Liberation Front. By 1991, however, the rebels were able to drive Mengistu into exile.

The trial of Mengistu and other Derg members that took place in Ethiopia ended in 2006. After 12 years, Mengistu was found guilty of genocide. In early 2007, he was sentenced, in absentia, to life in prison. The trial provided an opportunity for some of the victims of the Derg to tell their story. Ms. Teklu was one of them. “These people are luckier than our sons and daughters,” she noted about the convicted members of the Derg. “They are getting a fair trial.”

Should much-needed political change come to Zimbabwe, Mengistu will be, once again, stateless. Already the Ethiopian diaspora is filled with rumors of his possible future flight to North Korea. The victims of the Derg deserve that Mengistu Haile Mariam never makes it there.