Contrary to the sentiments of Lev Tolstoi, in my favorite novel, Anna Karenina, all dictators seem to be alike. Look at Kaddaffi. Who could stop looking at him, he is such a nut, and yet so shrewdly effective at enforcing a total control of power for 42 years. He dresses like a diva, talks like a moron, but rules cruelly and meticulously.
His compatriots in North Korea follow the same pattern, and extend their megalomania beyond the borders of their own countries to others that they, in their dangerous and unhinged fantasies, imagine to be hanging on their own every word. As with their Libyan brethren, these rulers have no compunction about wiping out every soul that populates their border, if it helps them to hold on to power.
The Cambodian Kmer Rouge were just such individuals, fueled by a crackpot ideology and ruthlessly efficient in their control and enforcement.
There is something about total power that unhinges the human mind in a way that is diagnosable, a kind of psychosis. Surely, someone should give it a berth in the dictionary of mental disorders.