The Lords of War - North Korea - They are the worst offenders of being violent against their own citizens

North Korea is the biggest offender when it comes to treating it's people like cattle. Not that cattle should be treated unfairly, but certainly the citizens of any country should be treated fairly. 

Each country that is discussed in The Lords of War is also treating their citizens unfairly.

North Korea is the poster child of all countries in relation to unjust behavior.