Exactly two years ago, I found myself standing before the freshly dug dirt surrounding 20 plain, white tombstones in the Syrian town of Khan Sheikhoun. It was two days after the regime launched a sarin gas chemical attack that killed an estimated 80 people.

I had gone to visit the graveyard after attending a memorial service in which I met Abdulhamid Al Yousef, a man who had buried his wife and nine-month-old twins after they suffocated in the attack. More than two dozen other members of his extended family had also died as he tried to rush people to a nearby hospital, which was also bombed.

I was sitting next to Mr Al Yousef when a visitor began trying to comfort him by recounting a hadith, one of the sayings attributed to the Prophet Mohammed. He told the bereft man that those who lose their children and endure calamity with patience will be rewarded on the Day of Judgment when they cross Al Sirat, the bridge that all must traverse to cross over hell to get to the gates of paradise.

Their children, he said, would have wings to fly across the bridge to eternal bliss. Mr Al Yousef seemed to perk up and, with urgency, asked if his wife would be there too with his nephew and niece. That seemed to give him a reprieve from dwelling on the horror of their final moments.

It made me recall how, a decade earlier as a student in the UAE, I attended a talk by a foreign correspondent, who talked about covering the Israeli war on Lebanon in 2006. He told us how he visited a mass grave in south Beirut for victims of the Israeli bombardment and the story of a man he interviewed, who had buried his wife and daughter that day. In that moment, I knew those were the stories I had to tell.

I remembered his account again after I visited those graves in Khan Sheikhoun but rather than offering answers, it left me confounded. I could not begin to comprehend the magnitude of that father’s grief, nor how he was supposed to grapple with injustice on such a scale. Two years on, he is no closer to justice and I am no closer to finding any answers.

Half a million people have been killed in Syria in eight years of war, a horrifying figure compounded by the fact that we have no idea how accurate it is, because the UN simply stopped counting at some point. Those 500,000 people are all dead, whether by poison gas, the method that sparked the most outrage, or barrel bombs, suicide attacks, starvation or torture. Thousands remain languishing in the Syrian regime's jails; half the country’s population have been forced to flee their homes.

Khan Sheikhoun was not the first major chemical attack. The 2013 Ghouta massacre, which killed more than 1,000 people, nearly prompted an American intervention in the conflict, one that was averted by a Russian-negotiated deal to eliminate all of Syria’s chemical weapons stockpile, which was clearly not carried out.

Khan Sheikhoun did prompt a show of strength by the US, which launched 59 cruise missile strikes on a military base in Homs. The war resumed in short order, once it became clear that was the extent of its response.

The initial outrage never translated into any form of accountability, there or elsewhere in Syria, even as human rights organisations, journalists, activists on the ground and the UN commission of inquiry documented every airstrike, every bombed bakery, every stray shell. When French President Emmanuel Macron promised retaliation if red lines were crossed with a chemical attack, and the US, France and Britain joined forces as recently as last week to vow an "appropriate response" if Bashar Al Assad used chemical weapons again, it was hard to imagine it would be followed by any real consequences to "hold [the regime] accountable". It hasn't happened before. Why would anyone believe it will happen now?

Indeed, I was never sure why, in the course of covering the Syrian war, anyone even spoke to me. As war crime after another was committed in places like Aleppo and Eastern Ghouta, it was quite clear that talking was of limited value.

I wondered for years why Mr Al Yousef spoke to me; or the doctors in Aleppo; the civilians under siege in Eastern Ghouta; or the medics who kept treating victims well after the world stopped watching.

Perhaps it was the belief that the moral arc of the universe would bend towards justice eventually. It took two decades for some of the former Yugoslavia’s war criminals to be brought to justice. Ratko Mladic was arrested in 2011, 16 years after his forces overran Srebrenica and murdered more than 8,000 civilians. But such notions of eventual retribution are too abstract in the rawness of the moment.

Khan Sheikhoun still gets bombed and shelled. Dozens of people in Douma were killed in a chemical attack last year, after surviving months under a brutal siege. The sheer relentlessness of the violence and the outrages has numbed us to their impact. Syria is the most well-documented conflict in history but that has made not an iota of difference to the response to atrocities.

But it matters that the victims, despite everything, still need to tell their stories.

Mr Al Yousef still wants to tell his story, which at the very least means we have an obligation to hear him, and others like him, even if we are never truly sure if justice will be done. Until then, we can only hope that one day, they get to tell their stories while facing the perpetrators of their misery in court.