There seems to be no limit to the dark revelations that have been revealed by the fall of the 54-year-old Assad regime in Syria.

Prisons have been emptied, revealing instruments of torture used on peaceful protesters and others considered opponents of the government. Piles of official documents record thousands of detainees. Morgues and mass graves hold emaciated victims with broken bodies, or at least some of them.

Many others did yet to be found.

For these and many other crimes, Syrians want justice. The rebel alliance that ousted President Bashar al-Assad last month is promised to hunt and prosecute senior figures of the regime for crimes that include murder, wrongful imprisonment, torture and gassing of their own people.

“Most Syrians would say that they can only achieve closure and end this dark 54-year era when these people are brought to justice,” said Ayman Asfari, president of Madaniya, a network of Syrian human rights organizations and other civic groups.

But even assuming the new authorities can find the suspects, accountability will be difficult to achieve in a country as vulnerable, divided and devastated as Syria. The experiences of other Arab countries whose despotic regimes have collapsed bear witness to the challenges: None of these countries – not Egypt, not Iraq, not Tunisia – managed to secure comprehensive, lasting justice for the crimes of earlier periods.

Syria faces some distinctive obstacles. The country’s new de facto leaders come from the country’s Sunni Muslim majority, while the senior ranks of the ousted regime were dominated by Alawites, a religious minority. That means prosecutions for Assad-era abuses could stoke sectarian tensions in Syria.

For years, the judicial system was little more than a tool for Mr. al-Assad, leaving him ill-equipped to deal with widespread, complex human rights abuses. Many thousands of Syrians could be implicated, more than could be prosecuted, raising questions about how to treat lower officials.

And after years of war, sanctionscorruption and mismanagement, it is a huge task just to fix the damage during the transition to a new government.

Nine out of 10 Syrians live in poverty. Cities lie in ruins. Houses were destroyed. Tens of thousands of people were unjustly detained for years or decades. There were hundreds of thousands killed in battles. Many are still missing.

The Syrians will need time and a lot of discussion to come up with a healthy accountability process, said Nerma Jelačić from the Commission for International Justice and Accountability, which has been gathering evidence against Syrian regime figures for years.

“These are things that take time and never happen overnight,” she said.

But there is immense pressure on Syria’s new leaders to start punishing the old ones, and the transitional authorities in the capital Damascus have vowed to do so.

“We will not relent in holding accountable the criminals, murderers and security and military officers involved in torturing the Syrian people,” Ahmed al-Shara, Syria’s de facto leader, said in post on Telegram in December. He added that he will soon publish “List No. 1” of high-ranking officials “involved in the torture of the Syrian people.”

Catching such figures will be difficult, if not impossible. Mr. al-Assad has found refuge in Russia, which is unlikely to give him up. Many of his top associates have gone into hiding, with some reportedly hiding in Lebanon or the United Arab Emirates.

Yet Syrian human rights groups in exile began laying the groundwork more than a decade ago, gathering evidence for the charges which were mounted in other countries – and one day, they hoped, in their own.

But Fernando Travesí, executive director of the International Center for Transitional Justice, which has worked with such Syrian groups, warned that before prosecuting in Syria, authorities must first win the trust of citizens by building a state that meets their needs.

This would avoid the missteps of countries like Tunisia, where the lack of economic progress in the years following the 2011 Arab Spring revolution left many people bitter and disappointed. By 2021, Tunisians had turned their fledgling democracy around, supporting a president who had grown increasingly authoritarian. Efforts to bring feared members of the security services and allies of the regime to justice are now functionally suspended.

“Any process of truth, justice and accountability must come from institutions that have a certain legitimacy and credibility with the population, otherwise it is a waste of time,” said Mr. Travesí. Providing key services, he added, would encourage Syrians to view the government “not as a tool of repression; he takes care of my needs.”

The transitional government can take basic but vital steps such as helping refugees who left years ago get new identity cards, deciding what should happen to property stolen or seized during the war, and providing stable electricity and running water. They will have to deliver humanitarian aid and economic improvements, though that maybe the only possible with the help of other countries.

And it must do all of this in an even-handed manner, otherwise Syrians may view the takeover efforts as selective or politically driven. After the overthrow of Saddam Hussein in Iraq in 2003, the US-led occupation and successive governments purged and blacklisted even lower-level officials in the former ruling party without due process, which analysts said undermined faith in the new system.

“The only way to heal the wounds with other communities is to make sure they are fairly represented,” Mr. Asfari said.

The Syrian authorities signal that they understand. They repeatedly promised to respect the rights of minorities and promised amnesty to soldiers who were forced to serve in the army of Mr. al-Assad. Most civil servants are allowed to stay on in order to keep the institutions functioning.

Any prosecution “must be a good process, otherwise it will look like a reckoning,” said Stephen J. Rapp, a former international prosecutor and former U.S. ambassador for global justice who has worked on Syrian abuses for more than a decade. “And that can play a key role in reconciling society and easing efforts to crack down, for example, against the children of parents who have committed these crimes.”

As an added complication, some of the documents that will be crucial to any prosecution have been damaged in the chaos following the fall of Mr. al-Assad, and regime prisons and archives of intelligence agencies were searched, looted or burned, said Mrs. Jelačić from the Commission for International Justice and Accountability.

Because Syria remains under war sanctionsher group and others trying to preserve these documents for future use in court are unable to operate in much of the country, further jeopardizing their efforts.

The wartime mass graves and torture devices are only the most obvious evidence of the abuses overseen by Mr. al-Assad and his father, Hafez.

Almost every Syrian has, in some sense, suffered injustice at the hands of the former regime. So it is not enough to prosecute individuals for crimes committed during the civil war, say veterans of legal efforts in other countries that have undergone political transitions.

Mr. Rapp called for a “broader truth-telling process” that could help “really begin to understand the system of state repression that has been Syria for the last 54 years, and this killing machine that has been Syria” since 2011.

One model could be Post-Apartheid Truth and Reconciliation Commission in South Africa, which heard the testimony of victims and perpetrators of rights violations, offered compensation to victims, and in some cases amnesty.

Mrs. Jelačić said that Syria will need a broader reckoning with the legacy of the Assad regime, which “does not contribute to divisions, but contributes to healing”.

Before the trial begins, experts said, Syria should overhaul its police and judicial systems and build a legal framework to address rights abuses, perhaps by creating a special court to prosecute the most serious crimes. An equally urgent priority is to find out what happened to the estimated 136,000 people who are missing after being arrested by the Assad regime and to identify the bodies discovered in mass graves.

But Syria cannot wait too long to prosecute former regime officials. Slow official justice leaves room for angry people to take matters into their own hands, which could start cycles of violence and deepen sectarian divisions. Individual revenge killings and threats against minorities favored by the Assad regime have already been reported.

After the revolution in Tunisia, long delays in the initiation of cases against former security officials reinforced the citizens’ feeling that their new democracy was bankrupt.

Lamia Farhani, a Tunisian lawyer who has long sought justice for the fatal shooting of her brother as he protested against the previous regime in 2011, said her country’s disenchantment has allowed the current president, Kais Saied, to dismantle its democracy.

“We had a democracy in its infancy that collapsed in the first storm,” she said. “And all this happened because there was no real reconciliation.”