Modern dictators seem increasingly blessed with longevity. Fidel Castro (1926-2016) was apparently no exception. Cuba's dictator, who turned his little Caribbean island country into a colony of the Soviet Union and then managed to hold on to absolute power even after the Soviet Union's well deserved demise, died finally at the ripe old age of 90. He had been ill and retired from government for much of the last decade. So his death seems somewhat anti-climactic - the opposite of the world-historical significance his death might have had 20, 30, 40, or 50 years ago. Still his departure does signify something, for he was the last example of a distinctly 20th-century species of dictator - the ideologue-prophet of secular utopianism.
The 20th century did not invent brutal dictators, nor will the 21st century eliminate them. But the 20th century did give us a distinctive type of totalitarianism rooted in powerful, prophetic ideologies of secular utopianism. There was the short-lived horror of Hitler's National Socialism, which provoked a world war, which was its undoing, when the Allies unconditionally defeated Germany in 1945. And there was the considerably longer lasting horror called Communism, which in varying versions came to power in Russia 99 years ago in 1917 and in China in 1949 and in various satellites and surrogates of those two terrible tyrannies. Castro's Cuba was both a Soviet satellite - dependent upon the Society Union for its utopian fantasies and to pay its bills, - and also a surrogate spreading the menace of violent Marxist-oriented revolution in both Latin America and Africa..
Apart from the brief (and somewhat improvisational) experiment of the revolutionary France in the last decade of the 18th century, only the 20th century has as yet ever produced such serious efforts to re-imagine and remodel human nature and totally transform human society along secular utopian lines - with predictably disastrous results.
Those disastrous results were evident early on. Revolutionary Emma Goldman recognized that about the Russian Revolution in her written account. (In the movie Reds, she is portrayed as telling John Reed, "It doesn't work.") Even so, such secular utopian ideologies flourished in certain intellectual circles throughout the 20th century as a quasi-religious, secular faith in an alternative future - despite all evidence to the contrary in the poor present.
Now that is all largely gone. People who might have embraced variations on the Marxist trope a generation ago are left floundering for a suitable substitute of comparably compelling imaginative appeal. Class conflict continues, of course, but doesn't inspire the way it used to. Instead the conflicts that most obviously - and dangerously - divide the world today are more traditional ones. They are age-old religious conflicts and traditional rivalries among nations and states in competition for relative advantage. The savage 20th century really is over.