ANLONG VENG, Cambodia — Thim Sam, a former Khmer Rouge soldier in a communist revolution that abolished property, profit and even money, has never tried his luck at the casino that opened recently near his home in northwestern Cambodia. He said he’s given up trying to fathom how the wheel of fortune turns.

At least 1.7 million of his compatriots died at the hands of the Khmer Rouge, yet just four people have been put on trial for some of the 20th century’s most horrific crimes. At a cafe a few yards from a fenced-off mound of earth said to contain the remains of Pol Pot, the Khmer Rouge’s murderous leader, Thim Sam said he joined Pol Pot’s forces out of desperation, took no part in the slaughter, and now “wants to forget.”

What to remember and what to forget is a question that torments Cambodia 14 years after the last Khmer Rouge stronghold fell here, on the Thai border. Victims clamor for justice while others, including members of the current government who once sided with the Khmer Rouge, want to avoid a full reckoning with the past.

Struggling to resolve these conflicting interests is a United Nations-backed tribunal set up in the capital, Phnom Penh, in 2006 with a mandate to judge Khmer Rouge “senior leaders” and others “most responsible” for the crimes of a regime that, between 1975 and 1979, killed at least a quarter of Cambodia’s population through executions, starvation and overwork in brutal labor camps.

After years of work at a cost of more than $150 million, the so-called Extraordinary Chambers in the Courts of Cambodia have convicted one person, a former prison warden called Kaing Khek Iev, 67, who ran the notorious Tuol Sleng torture center. Better known as Duch, he was sentenced in July 2010 to 35 years for crimes against humanity. In February, his sentence was extended to life after prosecutors appealed. Duch had appealed the earlier sentence as well, claiming he had merely been a junior official who followed orders.

A second trial now underway has put three aged, senior Khmer Rouge leaders in the dock. (A fourth defendant, Ieng Thirith, Pol Pot’s 80-year-old sister-in-law, is thought to be suffering from Alzheimer’s disease and has been judged unfit to stand trial.)

Demands that the tribunal widen its focus to include others “most responsible” have been rebuffed by the Cambodian government. Prime Minister Hun Sen — a former Khmer Rouge soldier who in 1998 declared that it was time “to dig a hole and bury the past” — has warned that opening new cases would risk civil war.

It would also risk severe discomfort for the government, particularly its security apparatus, which has worked closely with former Khmer Rouge officials suspected of a role in the communist movement’s “killing fields.” They include the Khmer Rouge’s former naval and air force commanders, Meas Mut and Sou Met, both of whom have held posts in Cambodia’s postwar military establishment and have been considered as possible defendants.

The U.N.-supported tribunal, located on the grounds of a Cambodian military compound on the outskirts of Phnom Penh, has been dogged from the start by bitter arguments over just how far it should go in delving into Khmer Rouge horrors and bringing those responsible to justice. More than 111,500 ordinary Cambodians have been bused in to witness the proceedings.