nuon chea is also on trial.e expressed his dissatisfaction with the proceedings including the witnesses. the 84-year-old left the hearing 15 minutes after the hearing began. many people were either executed or killed by starvation or forced leader. khmer rouge leader pol pot died in 1998. the tribunal is investigating the mass kilngs in the late 1970s. here's a brief history of the deadly regime. >> at the height of the cold war in the 1970s, cambodia was torn by a civil war.ed by chai fla c rebels took control of the capital phnom penh, and replaced a pro-american government. the communist regime led by pol pot decided to build a new society based on agriculture, buthe khmer rouge took social engineering to an extreme evacuating cities and sending the entire population to forced labor in rural villages. the regime also purged intellectuals and practitioners of traditional culture, resulting in the deaths of more than 1.5 million people. a basic agreement between cambodia and the united nations was reached more