Have brutal dictators been allowed to come to power since ww2?

Brutal dictators aren't "allowed" to come to power, they force their way into it.

A few prime examples who took over after World War II: Iraq's Saddam Hussein, Cuba's Fidel Castro, the Kim dynasty in North Korea, the Ayatollah Khomeini of Iran, Mullah Mohammed Omar in Afghanistan, and Romania's Nicolae Ceaucescu.