PHNOM PENH, Cambodia (CNN) -- Cambodia is a country that throws up the most staggering barbed facts that catch the mind and should stick inconveniently in our conscience.
Vietnamese retired television cameraman Ho Van Tay talks to CNN's Dan Rivers.
As I put together "Killing Fields: The Long Road to Justice" for CNN, I kept tripping across breathtaking statistics that seemed too incredible to believe.
Like, for example, a Yale University history professor's analysis of declassified military data that showed during America's bombing campaign over Cambodia from 1965-1973, the United States dropped more tons of ordnance on this tiny nation than the Allies dropped during the whole of World War II.
A total of 2,756,000 tons of explosives was dropped on Cambodia, compared with 2 million tons dropped during the Second World War, worldwide.
It goes some way to explain how and why the vicious, bloodthirsty and unstoppable phenomenon that was the Khmer Rouge came to power.
Simply put, faced with utter destruction by the United States or the promised utopia offered by Pol Pot and his ultra-communist henchmen, many Cambodian peasants chose the latter.
But that was before the killing started. Another head-spinning fact: After the Khmer Rouge swept to power in 1975 they killed a greater proportion of their own compatriots than any other regime in the 20th century. Watch a preview of "Killing Fields: Long Road to Justice" »
It's facile and pointless to make some sort of genocidal league table, but what happened in Cambodia in just three years, eight months and 20 days was certainly as awful and unfathomable as events in Nazi Germany, Stalin's Russia, Rwanda, Yugoslavia and Darfur.
I decided to revisit this terrible period, because it's now 30 years since the Khmer Rouge regime fell and finally a handful of its leaders are being put on trial at a special U.N.-backed war crimes court. It's garnered few headlines internationally. Perhaps Cambodia is just too remote, too forgotten, and too insignificant in many peoples' minds to warrant attention. But that is exactly why I felt it was vital to shine a spotlight on what happened.
Another remarkable fact: Pol Pot's men remained a potent force in Cambodia's power struggle that verged on civil war for almost 20 years after they were forced out of power by the invading Vietnamese -- a sinister culture of impunity that has strangled Cambodia while countries around it grew and prospered.
Even more incredible, the Khmer Rouge was backed by the United States, Britain, and other Western powers during the 1980s, despite the nightmarish mass-murder perpetrated by so many of the Khmer Rouge's Cadres. The United States viewed the Chinese-backed Khmer Rouge as a useful counterweight to Soviet/Vietnamese influence in Indochina. The U.S. doctrine seemed to follow the maxim "My enemy's enemy is my friend."
The impunity enjoyed by the top Khmer Rouge leaders is something the Extraordinary Chambers of the Courts of Cambodia is trying to address. But it's taking a very long time. And as I found out in making our program, the trial process itself is mired in corruption allegations, which some think may mean the entire process may collapse.
The United Nations is in a terrible bind over the issue. It's been forced into accepting a hybrid court system with the Cambodian government, which means the U.N. is not free to alone root out corruption quickly and surgically. Instead, as one defense lawyer told me, the corruption has been allowed to fester like a "cancer" eating away at the credibility of the trial. The prosecution, clearly worried about the court's credibility, also is pushing for the corruption to be addressed.
Already the costs for the proceedings are spiraling out of control: The budget will have swollen to more than $100 million by the end of this year, about $20,000,000 per defendant. Or to look at it another way: The trial is costing a mere $59 per victim.
What is also worrying is that the Cambodian Prime Minister Hun Sen, himself a junior figure in the Khmer Rouge, has said that the trial should be limited to the current five defendants -- and no more. He has said that expanding the circle of prosecution risks the stability of the country. But that means in practice that many of those involved in the slaughter during the Khmer Rouge period would remain unpunished.
The most notorious camp in Phnom Penh, called S21 or Tuol Sleng, was set up in a former school. The camp was designed to extract confessions from internal enemies of the regime, using whatever means deemed necessary. The result, according to meticulous Khmer Rouge records and survivor accounts, was the most brutal and sadistic torture camp imaginable: More than 14,000 prisoners were killed after enduring horrendous torture.
The chief interrogator at S21 was a man called Ta Chan, who led a team of interrogators. He has never officially been charged with any crime.
After quite some effort, we found out where Ta Chan lives. When we arrived at his modest wooden house in the far west of Cambodia, I got a glimpse of him. But he was apparently too scared to face our cameras, leaving his son to do the talking. His son said Ta Chan was old, and his health was bad, and that none of the family wanted to talk about the past.
By a stroke of luck we obtained and salvaged an old, barely functioning tape, shot by a Thai cameraman 10 years ago, that had never been broadcast. It contained the grinning image of Ta Chan showing off another prison he ran for the Khmer Rouge after they'd been forced to abandon S21. Here he was -- one of the most notorious figures of one of the most bloody regimes in the world -- and after twenty years, he was still in the prison business.
Now, finally Ta Chan's face will be known to the world. The question is, will he ever face trial for the heinous crimes that survivors say he committed?