Back then, many people working at the intersection of technology and human rights shared a belief in the power of social media and digital connectivity to do good, according to Jay D. Aronson, head of the Center for Human Rights Science at Carnegie Mellon University. People thought that “if we’re able to document these war crimes and these human rights violations and we’re able to share them with the world, then that will create political will that will lead countries to intervene and protect vulnerable populations,” he says.

Spurred on by such optimism and the encouragement of Western politicians, such efforts made the Syrian conflict the most thoroughly documented in human history.

Thanks to frontline investigators like Houssam Alnahhas, local outfits like the Syrian Archive, and online analysts from Bellingcat, detailed information about what was happening on the ground was there. Someone just needed to act on it.

When Alnahhas returned to Turkey with the evidence he’d collected in Kafr Zita and Talmenes, he met up with a British chemical weapons expert who tested some of the samples. The analysis confirmed that they contained a high enough concentration of chlorine to kill people. The evidence clearly showed that the Syrian government, the only fighting force with helicopters at the time, had indiscriminately bombed civilians with chlorine gas—a war crime.

International media picked up on the story; human rights organizations published reports; the Organisation for the Prohibition of Chemical Weapons launched a fact-finding mission. The remaining samples were given to the Western governments who were interested, and then Alnahhas waited.

Nothing.

Last summer I met Ahmad al-Mohammad, a soft-spoken activist and communications director of the Syrian Institute for Justice, in Istanbul. He had been a 19-year-old agriculture student at Aleppo University when the uprising began in 2011.

The Syrian protesters were optimistic back then. The US had just led an international military intervention to protect civilians in Libya from the advancing army of former leader Muammar Qaddafi. “We listened to a lot of speeches from the president of America, Obama,” said al--Mohammad. “We had hope, honestly, that the West would intervene and remove Bashar al-Assad.”

And in 2012, Obama declared the use of chemical weapons in Syria a “red line.” “The world is watching,” he warned Assad. “If you make the tragic mistake of using [chemical] weapons, there will be consequences, and you will be held accountable.”

Obama’s resolve was put to the test on the morning of August 21, 2013. Syrian government forces launched rockets loaded with sarin gas, a deadly nerve agent, at the rebel-held enclave of Ghouta, on the outskirts of Damascus. It was by far the deadliest and most visible chemical attack of the war. Syrian activists quickly uploaded photos and videos of the casualties, many of them women and children, their faces blue from suffocation. The estimated death toll ranged from around 350 to more than 1,400.

Emily Haasch

The US—driven forward by the “red line” rhetoric—prepared to launch military strikes. The regime hunkered down. But at the last minute, Obama pulled back. Instead of using force, he opted for a deal brokered by Russia, which resulted in the Syrian government’s signing on to the Chemical Weapons Convention and agreeing to declare its stockpiles and destroy them by mid-2014.

For people in opposition-held areas, the decision was crushing. “We lost hope that anyone would [stand] up and say enough … killing civilians inside Syria,” Mohammed Abdullah, a Syrian photographer who goes by Artino and who was in Eastern Ghouta at the time of the attack, told me.

And then, despite its promise to dismantle its chemical weapons program, the Syrian government launched chlorine gas strikes in April 2014—the ones Alnahhas documented. They were another clear violation of Obama’s red line. When the outside world again failed to take strong action, Assad’s government continued to push the envelope. According to a report by the Global Public Policy Institute (GPPi), a think tank in Berlin, this was when the Syrian government began integrating the use of chemical weapons, especially chlorine gas, into its “arsenal of indiscriminate violence.”

Assad’s strategy was directed against civilians living in opposition-held residential areas far from the front lines. Life-sustaining social institutions—bakeries, hospitals, and markets—were often targeted with a brutality that forced people to choose between surrender, exile, and death. Tobias Schneider, one of the GPPi report’s authors, refers to it as the “military utility of crimes against humanity.” The use of chemical weapons was “the last couple of meters,” he told me.

Heavier than air, poison gas sinks into basements and bunkers, suffocating and terrifying people sheltering from conventional bombs and weapons. Even if the chemical attacks often didn’t kill large numbers of people, they showed that “there is absolutely nowhere you can hide and there’s absolutely nothing [the regime] can do that will make the international community stop [the violence],” Schneider added.

The Syrian government has used chemical weapons more than 330 times so far, according to data collected by GPPi. The vast majority of these incidents—more than 300 of them—took place after the attacks in Ghouta, Kafr Zita, and Talmenes.

For Alnahhas, the lesson was clear.

“After providing evidence all the time, at a certain point you stop to believe that it will be effective,” he said. “The main thing that I know is that neither I nor the people inside Syria trusted the international community anymore.”

Many people who had been documenting the war were forced to leave Syria as it grew more violent. Some decided to focus on putting their lives back together, to finish their studies or start families. For many of those who remained in Syria, the work of documentation became too dangerous as the areas they were in fell under regime control.

But other activists have decided to take a longer-term view. Although the documentation efforts have failed to shift the course of the war, Syria has produced arguably the largest evidence base on war crimes ever recorded. Civil society organizations are sifting through the data, organizing it, and using it to build case files for prosecutions. Courts in Germany, France, and Sweden are already trying cases. Arrest warrants have been issued for several high-ranking members of the Assad regime, and charges have been brought against European companies for violating sanctions imposed on the Syrian government. The Open Society Justice Initiative (OSJI), a human rights litigation team, is working with the Syrian Archive to develop case files on a number of attacks, including the attack in Talmenes that Alnahhas documented.

Al-Mohammad has scars on his face from having his jaw fractured in seven places when security forces threw him from the second story of a building during a protest in 2012.

“Open-source information has radically transformed how we investigate, collect, and analyze information,” Steve Kostas, a lawyer with OSJI, told me by email. “We use it to establish a factual narrative of the attacks, to identify possible witnesses, [and] to identify and learn about suspected perpetrators.” Still, says Beth Van Schaack, a visiting professor at Stanford Law School who previously worked on Syria at the US State Department, the prosecutions so far have been “mostly against lower-level individuals, opposition figures, [ISIS] members, and not the kinds of war crimes that have really come to characterize this war.”

Holding the true architects of the Syrian government’s war strategy responsible would require unity from other governments. But Russia has repeatedly blocked efforts to start an international process of justice and accountability; for example, it vetoed a 2014 UN Security Council resolution referring Syria to the International Criminal Court. The UN created a body called the International Impartial and Independent Mechanism to gather evidence for future cases, but “until this moment, we don’t have any court or entity that has jurisdiction over crimes committed in Syria,” says Deyaa Alrwishdi, a Syrian lawyer who has been involved in accountability efforts since 2011.

It now seems all but inevitable that the Assad regime—helped by Russia and Iran—will emerge victorious from the war. It may be decades, if ever, before it’s truly held accountable.

“We get hope when we look at the former Yugoslavia and how victims and survivors from Bosnia and Herzegovina did eventually get justice. That gives us hope to keep holding on,” al-Mohammad, from the Syrian Institute for Justice, told me in Istanbul.

He has scars on his face from having his jaw fractured in seven places when security forces threw him from the second story of a building during a protest in 2012. Two members of the documentation team he manages in Syria were killed while carrying out their work. And he has watched countless hours of video showing one brutal atrocity after another, giving him nightmares. His family is still in Syria, and he worries that they will be punished by the regime as retribution for his actions.

Activists in Syria have documented the presence of chemical weapons’ shell casings with photos like this one, in the hope that they'll provide evidence of war crimes. Emily Haasch; illustration source imagery courtesy of the author

It’s hard for him to see a path forward or a way to return home. “Me and my friends, we sit down and we talk about it a lot … we don’t really know where we are going,” he says. “At the end of the day, people like us—our future in a Syria without justice is just death or prison.”

Yet al-Mohammad and others have continued to record evidence of the crimes taking place. At some point, he says, it stopped being about what the international community would or wouldn’t do; it became about Syrian people taking control of their own stories. “My goal became to document my country’s history,” he says.

When I met Alnahhas in Gaziantep earlier this summer, he told me he felt the same way. We talked at an outdoor café, surrounded by the mundane bustle of a busy town. Syria, just a few miles down the road, seemed far away. In the years since his dangerous trip to document the chemical weapons attacks, he had gone to a Turkish university to finish his medical degree, married, and started a family. He couldn’t imagine returning home.

He told me about three of his friends, young students who had volunteered to provide care to injured protesters in the early days of the uprising. They were stopped at a regime checkpoint, and medical supplies were found in their car. Days later, their bodies were returned to their families, burned beyond recognition. Years later, his efforts to document the chemical attacks in Kafr Zita and Talmenes hadn’t changed anything; people were still being murdered with impunity.

“At the same time,” he said, “you cannot simply say that I’ll not continue.” If nothing else, documenting has given him and others like him a certain mission. “History is written by the strongest,” he said, echoing the familiar adage. “Without proper evidence … the regime will be able to, at a certain point, say ‘No, this never happened’; [it] will be able to manipulate the history of the Syrian crisis maybe to avoid punishment. So this is our responsibility.”

Eric Reidy is a journalist based in the Middle East.