?He could be very entertaining,? Stalin?s niece, Kira Allilueva, told biographer Robert Service in 1998. The dictator had her jailed in his last round of purges after World War II, but she still remembered how kind he had been to her when she was a little girl, how he took her on his knees and sang songs to her. He also wrote limpid poetry in Georgian as a youth, read Dostoevsky, and his subordinates saw him as a considerate boss.

He had millions of people killed, which is why, until Service?s recent book, Stalin: A Biography, people were reluctant to write about his human side. Yet a moment?s thought will tell you that the great dictators could never have achieved such power over people if there was not something attractive about their personalities.

The current wave of books and films about human monsters began with a couple of ground-breaking Italian biographies that showed the human side of Mussolini, but he wasn?t really in the first team as a mass murderer. Service?s biography of Stalin is in a different league ? and so is Berndt Eichinger?s ground-breaking film on the last days of Hitler, The Downfall.

Kind and gentle

It is the first German film to tackle Hitler directly. Set in the last twelve days of Hitler?s life as the Soviet army fought its way towards his bunker in central Berlin in April 1945, it documents his rages and his self-pity, but it also shows him as an ordinary human being. He says ?please? and ?thank you?. He eats pasta. He is kind to the terrified women who continue their secretarial duties as the apocalypse rages overhead. When he finally marries his mistress Eva Braun (which he always refrained from doing because, he said, he was wedded to the German people), he is implicitly accepting that it is all over? but he kisses her gently on the lips.

Admitting that Hitler and the other great murderers were human is painful, but to deny it is to absolve ourselves of any moral connection to what happened. Whatever the risks involved in acknowledging our common humanity, they are outweighed by the need to understand that it is human beings who commit the atrocities.

Consider Ernesto ?Che? Guevara, the revolutionary hero whose iconic image once graced millions of students walls. There is no doubt that injustice inspired genuine rage in him. Since he never got to rule, his image is unsullied by any knowledge of what he would have done if he actually had power.

Only human

There has been a film about Che, too. The Motorcycle Diaries follows the epic trip he and a friend made up the length of Latin America on an old Norton 500 in 1952. It documents how these young sons of privilege had their eyes opened to the realities of poverty and exploitation in Latin America. The film ends just before Che joined Fidel Castro in his Mexican exile and began his own meteoric revolutionary career.

Che comes across as an attractive human being, and his dedication to the poor is clearly genuine. But the ideology he espoused was Marxism, and he did not water it down. He used to prostrate himself before portraits of Stalin, and he advocated ?relentless hatred of the enemy that...(transforms) us into effective, violent, selective and cold killing machines.? If he had led a successful revolution in Bolivia, instead of dying in the attempt in 1967, there would certainly have been mass killings.

Mass murder in the name of a principle is as human as apple pie, borsht and steamed rice. The potential mass killers live among us, as they always have. They often have perfectly good manners, and some even have high ideals. And the only way the rest of us have to keep them from power is to remember always that the end does not justify the means.