December 5, judges at the tribunal will announce whether "Comrade Duch" can be held accountable under the doctrine of "joint criminal enterprise," a controversial form of liability resembling conspiracy.

Haggling over the applicability of the charge has delayed the start of the Tuol Sleng torture chief's trial for months. As recent briefs filed with the court show, the dispute is actually just the most recent flashpoint in a much larger legal debate. So while it may seem highly theoretical, the judges' decision on JCE will have relevance both in Cambodia and beyond -- in creating a historical record reflecting the depth of Duch's involvement in Khmer Rouge atrocities, as well as potentially setting a precedent for other international and hybrid courts.

After the Co-Investigating Judges issued their indictment against Duch in August, it was subsequently appealed by the Co-Prosecutors. Along with urging the court to charge the defendant under the Cambodian Penal Code of 1956, they argued that he should be held accountable under the concept of JCE, which exists when two or more people participate in a common criminal endeavor, sharing a common criminal purpose.

To help resolve the debate, the court requested outside legal opinions from Professor Antonio Cassese, editor-in-chief of the Journal of International Criminal Justice, the McGill Centre for Human Rights and Legal Pluralism, and Dr. Kai Ambos of Germany. Their briefs were received by the tribunal in late October and, as is often the case with expert opinions, did not render a consensus.

The most extensive brief came from Cassese, who was the first president of the International Criminal Tribunal for the Former Yugoslavia (ICTY). Lawyers for Ieng Sary had tried to disqualify Cassese's opinion as biased -- a request that was denied by the court -- because he served on the appellate panel of the ICTY, which elucidated JCE as a mode of criminal liability.

Not surprisingly, Cassese delivers a relatively favorable opinion of JCE and its potential applicability before the ECCC. In order for this form of liability to be relevant, it must have been universally understood as a mode of criminality during the period of 1975-1979.

JCE "doctrine is a crucial part of international criminal law, ensuring that individual culpability is not obscured in the fog of collective criminality and accountability evaded," Cassese writes. "The principles of JCE as a mode of criminal liability crystallized after World War II and were customary rules of international criminal law by 1975."

In other words, Cassese claims Khmer Rouge leaders should have been aware of the principles of JCE, even if a cohesive definition of the term had not yet been created.

"JCE liability should be applied in appropriate cases at the (ECCC) to ensure accountability for the full gravity of crimes, where the exact role that each participant played in a common purpose may be obscured by the massive scale and complexity of the crime," he writes. "Recognizing this mode of liability would ensure consistency in the application of law among international and hybrid tribunals that historically have applied JCE liability and that are continuing to apply the doctrine today in contexts as diverse as the former Yugoslavia, Rwanda, Sierra Leone, East Timor, as well as Iraq."

Cassese goes on to define the three different types of JCE liability. The distinctions are important, because some forms are more controversial than others:

JCE 1: This is the "basic" form, wherein all participants act pursuant to a common design and possess intent to commit the crime, even if each participant carries out a different role and offers varying levels of contribution.

JCE 2: This is the "systemic" form, a variant of JCE 1 applied to persons carrying out tasks in a institutional framework, such as a concentration camp.

JCE 3: This is the "extended" form, where another perpetrator commits a crime that, though outside the common design, was a natural and foreseeable consequence of effecting the common purpose.

With each form of JCE liability, varying degrees of responsibility in the conspiracy are to be reflected in sentencing.

JCE 1 is the most straightforward form, and thus, the least controversial. If you participate in a conspiracy to commit a crime, knowing what the outcome will be, you are responsible to a certain degree even if you are not the "trigger man."

With JCE 2, responsibility becomes a bit more hazy.

"Plainly, in an internment camp where inmates are severely ill-treated and even tortured, not only the head of the camp, but also senior aides and those who physically inflict torture and other inhuman treatment are responsible. Those who discharge administrative duties indispensible for the achievement of the camp's main goals -- for example, to register the incoming inmates, record their death, give them medical treatment, provide them with food or prevent the detainees from leaving -- may also incur criminal liability," Cassese writes.

He continues: "However marginal their role, they constitute an indispensible cog in the murdering machinery."

Do they? I can understand how those employed in camps who mistreat and torture people should be held accountable criminally. But would Khmer Rouge cadre, forced by Angkar to serve food or, say, take pictures of detainees (like Nhem En), really be considered part of a criminal conspiracy? It seems this could be casting the net of liability a bit too wide.

Indeed, Ambos writes that JCE 2 should only be narrowly applied, and that the standards of JCE 3 only constitute aiding and abetting, not co-perpetration.

JCE 3 is, undoubtedly, the most debated form of JCE liability. Cassese writes that it applies to participants who agree to the main goal of a common criminal design, "but do not share the intent that one or more members of the group entertain to also commit crimes incidental to the main crime." Such participants must have been able to foresee the incidental offenses and took the risk anyway.

To illustrate, Cassese cites the "Essen lynching" case, in which seven Germans where accused of bringing about the deaths of three British prisoners of war. A German army captain had instructed two men to escort the POWs to a nearby unit for interrogation, saying loudly, so a gathered mob could hear, "that the escort was not to interfere with the crowd if it molested the prisoners." As the POWs were marched through Essen, they were shot at and beaten, eventually dying from their injuries.

The captain was convicted for the deaths and sentenced to death by hanging. Other participants in the incident were either imprisoned or sentenced to death, given their degree of responsibility.

JCE 3 has come under a great deal of scrutiny. The concept of a "foreseeable outcome" is highly subjective. As Ambos writes, "the foreseeability standard is neither precise nor reliable ... one cannot blame the member of the JCE for not having withdrawn from the criminal enterprise: how and why should he do so if he does not even foresee the criminal result with certainty?"

There are no easy answers to these questions. As judges at the ECCC review JCE in relation to Duch's case, it seems they could arrive at several different conclusions: JCE is not applicable, all forms of JCE are applicable, or only certain forms of JCE are applicable. I cannot predict what they will decide, but am certainly anticipating the decision.