Talking about the Khmer Rouge with Tara, a Cambodian taxi driver, all he knew was that in his village, some 30-somethings like him once went to Phnom Penh to hear the trials of Khmer Rouge leaders. "Vehicles came to pick you up, and you even got a free meal," said Tara, who lives in a village not far away from Siem Reap.

Many Cambodians still remember the Khmer Rouge era, which ended over 30 years ago. It is estimated that during the ruling by the Khmer Rouge, which lasted 44 months, anywhere between 400,000 and 3 million people, out of a population of less than 8 million, died of hunger, forced labor, disease, torture, political persecution, or from other unnatural reasons. The Khmer Rouge is still a frequent topic in Cambodian and other Southeast Asian media.

One month ago, I attended an ASEAN meeting at Siem Reap, and read a report published by the Cambodia Daily on how a Cambodian man didn't learn until a recent trial of the Khmer Rouge that his wife, who disappeared 34 years ago, actually died after being imprisoned in a concentration camp.

More than a few tourists arriving in Cambodia are also very interested in that period of history. In the night fair at Siem Reap, one can find biographies written by Westerners about Khmer Rouge leader Pol Pot, and books revealing the horrors of Security Prison 21, that once confined "political criminals."

According to the Thai media, Pol Pot's graveyard in northern Cambodia has become a newly developed tourist site.

In Siem Reap, trials of the Khmer Rouge leaders are ongoing. Case 001, on Kang Kek Iew, head of the Security Prison 21, was closed at the beginning of this year, when he was sentenced to life imprisonment. The current case 002 had four defendants, Nuon Chea, Khieu Samphan, Ieng Sary, Ieng Thirith, and all of whom were leaders of the Khmer Rouge.

That part of history has been taught at high schools since 2009, according to arrangements by Cambodia's Ministry of Education, Youth and Sport. Although that part of history is already remote to 30-somethings like Tara, the memory of the Khmer Rouge hasn't completely faded out.

Historical events can be tucked into a corner for a while. However, they won't vanish, but will always jump out later in their own way. 

When people mention the Khmer Rouge, many might be reminded of the support China once gave it. This is a problem that cannot be avoided. No matter whether China wants it or not, as China's relationships with Cambodia and Southeast Asia grow closer, people will allude to that history.

In fact, in the US pivot to Asia, one important strategy is to take advantage of the Cold War legacy. The historical shadow of the Khmer Rouge lies behind recent Western finger-pointing that Cambodia is risking the destruction of ASEAN unity over the South China Sea issue just to cater to Beijing.

An interesting phenomenon is that the Americans, who also provided support to the Khmer Rouge due to their own needs in the Cold War, have now become the third largest donor of the tribunal putting the Khmer Rouge leaders on trial. In comparison, in China, this tribunal is even barely mentioned by the media yet.

Is it true that the US, which is seeking a pivot to the Asia-Pacific region, really has no historical burden? Absolutely no.

US journalist Joel Brinkley, in his book Cambodia's Curse, states that from 1970 to 1975, the US provided the Lon Nol administration with military and economic aid worth as much $1.85 billion, or $9 billion if calculated in 2010 dollars.

Who has studied about how many lives such aid cost in Southeast Asia?

But since the beginning of this year, the US government has done two things to address historical issues in Southeast Asia.

First, it promised to spend $9 million to clear land mines left by the Vietnam War. Statistics show that 90 million cluster bombs were drooped on Laos, but were left unexploded at the time. These bombs are still killing Laotians today.

Second, in August, for the first time since 1975, the US embarked on a joint project with Vietnam to clean up the toxic remnants of Agent Orange. During the Vietnam War, US planes sprayed millions of gallons of the defoliant Agent Orange over Vietnam's jungles to destroy the hiding places of the Viet Cong. Four decades on, the chemical is still harming the health of ordinary Vietnamese.

Through these actions, is the US simply seeking to fix its image? Certainly not. These projects have been openly included as part of the US "back to Asia" strategy. Just like providing support to the tribunal putting the Khmer Rouge on trial, the Americans are trying to play the role of a responsible leader in Southeast Asia.

It's probably time for us to seriously consider how we should deal with the historical issue of the Khmer Rouge.

The author is a senior editor with People's Daily. He is now stationed in Bangkok. dinggang@globaltimes.com.cn