Jeffrey Winters and Ridarson Galingging, Jakarta

Most people would agree that it is unjust to prosecute someone for a legal action which is later made into a crime by passing a new law. Retroactivity, as it is called, is unfair because citizens must be confident that their legal actions cannot later be turned against them as illegal.

But how absolute is the retroactivity principle? Are there any special circumstances under which retroactive enforcement of a law is justified?

Although the Indonesian Constitutional Court (CC) split 5-4 in its recent decision on the country's terrorism law, it is important to note that all of the judges were in agreement that retroactive enforcement is sometimes justified.

In accordance with principles of international law that have been in effect at least since the end of World War II, the judges were unanimous in the view that under special circumstances retroactive enforcement should be allowed.

Thus, the real controversy at the heart of the recent decision by the CC is not the broad issue of whether a law can ever be enforced retroactively, but rather the narrower question of whether special circumstances existed in the Bali bombing case to justify retroactive enforcement.

So why did the judges split in their opinion? The answer is that five judges held that the Bali bombing was an "ordinary crime," while the dissenting judges argued that the crime was "extraordinary." Thus, the majority agreed that retroactive enforcement is justified is some cases, just not in this particular case.

What this means is that much of the debate focusing on the important principle of retroactivity is actually beside the point. It is a philosophical distraction from the real meaning and intent of the majority on the CC. This decision was more political than legal.

The judges who prevailed went to great lengths to make sure that the Bali bombing had no special status as a terrorist act. By insisting that the bombing was simply a horrible but ordinary case of murder, the judges crossed the line from pure legal reasoning into the realm of politics. Their objective was less to declare and uphold an absolute legal stance on retroactivity, and more to strike a blow against the prosecution of violent Muslim extremists as terrorists.

There are two very strong reasons why the judges could and should have allowed retroactive enforcement of the terrorism law in the Bali case. They deliberately chose to downplay or ignore both reasons.

The first concerns the crucial issue of avoiding post-hoc criminalization.

The single most important argument against retroactivity is to avoid oppression through the criminalization of non-criminals. Allowing retroactive enforcement of the terrorism law should have been easier for the judges because no post-hoc criminalization occurred in the Bali bombing case. The actions of the conspirators were criminal whether they were prosecuted under the terrorism law or the ordinary criminal code.

By contrast, if a citizen legally shouts "the Minister X is stupid" at a rally, and then a law is passed making it illegal to say high government officials are stupid, then a legal action has been retroactively made illegal. Everyone would agree that it is unjust to enforce the new law against the rally participant who said the Minister was stupid.

The Bali bombing case is the opposite of this example. The conspirators committed the crime of killing people, severely injuring people, and destroying property. Passing the terrorism law after the bombing did not suddenly transform innocent people into criminals -- which is the single most important reason to block retroactivity. It simply redefined their "normal" crimes as special or "extraordinary," in this case blowing up people with the specific goal of terrorizing a society.

When a new law transforms innocent citizens into criminals, all government justifications for retroactivity should be ignored and the court should always invalidate the law. But when the actions of the defendants are already serious crimes, the door is wide open for judges to weigh possible government justifications for retroactive enforcement of new laws passed after a crime is committed.

For instance, a government might want to do more than just punish nightclub or hotel bombers as common murderers to send the message that they are different from someone who kills a lover or co-workers in a rage. A government might want to send a clear signal to its citizens and to the world that terrorism is a particular kind of threat, and that special actions will be taken to confront it.

The Indonesian government clearly felt that the benefit of reducing fear from terror in Indonesia outweighed the minor disadvantage of retroactively prosecuting cold-blooded murderers as "terrorists" rather than simply as "ordinary murderers." It is important to note also that the new law did not increase the sentences the defendants would face.

On these solid grounds, the Indonesian government made the right decision to proceed with the prosecutions under the new terrorism law rather than under the existing criminal codes.

The second reason the CC judges could have used to uphold retroactive enforcement of the terrorism law was that the Bali bombing was an "extraordinary" crime involving special circumstances.

On very weak grounds and reasoning, they deliberately ignored the arguments in favor of treating the Bali bombing as an extraordinary crime.

International jurisprudence dating back at least to the Nuremberg trials holds that the retroactive enforcement of laws is justified when a crime is "extraordinary."

Another example is terrorism. The point is not just that many people are killed (this is a common occurrence around the world), but rather that the people killed are just incidental to the broader goal of spreading fear and sowing instability.

Again, killing people is already a crime. But governments routinely treat murders differently based on the motive involved. And numerous UN Conventions to which Indonesia is a signatory uphold the principle that this can be done retroactively, particularly in the case of terrorism.

It happens also that the Bali bombing involved a network of conspirators that had international linkages, adding to the "extraordinary" character of the crimes and of the threat. Existing criminal laws dating back to the Dutch colonial era were inadequate for pursuing crimes with this trans-national character.

To support their decision not to relax the retroactivity principle, the judges first had to dismiss the claim that the Bali bombings constituted extraordinary crimes. Although the majority decision cites the testimony of expert witnesses, not one provided legal grounds or rationales undermining the Indonesian Justice Ministry's argument that the terrorist bombings in Indonesia were extraordinary crimes.

To arrive at what can only be described as an extremist legal interpretation, the judges for the majority had to ignore not only the well-founded arguments of the Indonesian government, but also at least a dozen international conventions that treat attacks such as the Bali and Marriott bombings as terrorist acts, and thus as extraordinary crimes.

The obvious question that remains unanswered is why these judges chose to adopt this extremist position. We believe that a key part of the answer can be found in looking at the political backgrounds of the majority and dissenting judges, as well as different training the judges have received.