I nominate this man as the most destructive leader of all time
His reign may have only lasted four years, but those four years were a living hell for Cambodia.
His name is Pol Pot.
Upon taking over Cambodia in the mid 70s, he was made the general secretary of the new communist regime called the Khmer Rouge. Under this regime, the country was renamed Democratic Kampuchea.
Upon taking over the country, this new government did all of the typical communist country stuff such as collectivizing everything, restricting religious practice, and being overall authoritarian.
The Khmer Rouge took these things further. They abolished currency, limiting the communes within to bartering with each other. They also sought to destroy all traces of the country’s imperialist past and in the process, ended up weakening its educational institutions. One of those things they did was kill people whom they believed were intellectuals (even for just knowing a foreign language or wearing glasses). Even the family unit wasn’t safe; the government often broke up extended families as they favored nuclear families. Marriage required government permission which was rarely (if ever) granted to couples from different classes. Sex outside of marriage was punishable by death.
At this point, life in Kampuchea sounds more like a dystopian novel than it does a regime from actual history. But it gets even worse.
What really makes Pol Pot take the cake is the economic policy which was undertaken. In my answers about overpopulation, I stated that industrialization allowed increased food production to accommodate the growing population. Every school of economics (even the Marxist one) agrees that industrialization was essential for rising living standards.
It only stands to reason that undoing those industrial advances would lead to catastrophe.
Well, the Kampuchean government did just that. They forced the people to leave the cities and work in the fields. Anyone who refused was shot on the spot. In addition to all of this, the government waged a genocide against the Vietnamese within the country.
The results were catastrophic. In total, roughly 1 in 4 Cambodians perished during those four years.