The Syrian war is proof of the collective failure of diplomacy, the UN envoy to the country, Geir Pedersen, said on the eve of the conflict's ninth anniversary of the conflict.
The Syrian Observatory for Human Rights in Britain said it had identified 384,000 deaths since protesters first took to the streets in 2011 demanding the resignation of President Bashar Al Assad.
The observatory said that did not include the nearly 88,000 civilians tortured to death in Mr Al Assad’s detention centres and prisons.
It did not include the 4,100 missing loyalist fighters, or the more than 3,200 civilians and fighters abducted by ISIS, and the 1,800 people taken by other extremist groups.
The war monitor said they were not included because it could not accurately verify those or the other untold number of other casualties in the war.
The Syrian Network for Human Rights has placed the number killed in Assad's jails at 14,391 people between March 2011 and March 2020.
Almost 128,000 have never emerged from the regime’s prisons and their fate remains unknown, the network said.
Those who have been released give harrowing accounts of the conditions inside.
It was so difficult to confirm deaths in the conflict that the UN gave up in 2016, saying in its last update that there had been 400,000 fatalities or about 2 per cent of the total population of Syria.
A year later, then UN human rights head Zeid Al Hussein said the conflict was the worst man-made disaster since the Second World War.
Since then, little has changed.
The ninth anniversary of the war is a sobering reminder of the humanitarian catastrophe that has devastated a country, had a ripple effect across the region and Europe, and changed the international system forever.
The observatory estimated that 2 million people have been wounded or left with permanent injuries.
The UN said nearly 12 million have fled their homes.
The uprising began on March 15, 2011, when protesters took to the streets of Deraa in south-west Syria, and quickly spread across the country.
People demanded an end to the rule of the Assad family who had governed for 40 years.
Within weeks, reports began to emerge of a rising death toll as security forces opened fire on protesters in the start of a brutal crackdown against what were, initially, peaceful protests.
In response, people took up arms to defend the demonstrations.
"A decade of fighting has brought nothing but ruin and misery," UN Secretary General Antonio Guterres wrote on Twitter this week. "And civilians are paying the gravest price.”
The observatory, which draws its information from sources inside Syria, said that more than 116,000 deaths had been civilians, with 22,000 children and 13,000 women among them.
There have also been countless possible war crimes and crimes against humanity.
There are claims that chemical weapons have been used hundreds of times, mostly by the Assad regime, killing thousands and sometimes provoking a limited US military response.
Mass torture, summary execution, rape, robbery and destruction of property have been widely used.
Today, the death, displacement and human rights abuses continue as Mr Al Assad, and what is left of the opposition backed by foreign powers, pursue competing aims in what could be the final throes of the war.
In the north-west province of Idlib, a regime offensive against Turkish-based rebels has forced almost a million people from their homes since December in the largest single wave of displacement since 2011.
The clashes have also led to a sudden rise in military deaths, with violence increasing after 33 Turkish soldiers were killed in a regime air strike in February.
A ceasefire between Ankara and Moscow came into force this month but peace is tenuous in Idlib, which is the last rebel stronghold in Syria.
For Mr Al Assad, retaking Idlib would be the closing victory in his government’s nine-year battle to retake the country.
His grip on power was weakening before Russia came to his aid in 2015, and he now controls more than 70 per cent of Syrian territory, bolstered by support from Iran and its Lebanese proxy Hezbollah, as well as dozens of smaller Tehran-supported militant groups.
The territorial gains have come at a heavy cost to Syrian forces, which have lost 129,476 soldiers, allied forces and militiamen since the start of the war, including 1,697 members of Hezbollah, the observatory said.
Among opposition groups, almost 57,000 rebels have been killed, as well as 13,624 members of the Kurdish-led Syrian Democratic Forces, which led the US-backed campaign against ISIS.
Deaths of ISIS fighters and those loyal to Al Qaeda-affiliated Hayat Tahrir Al Sham, formerly known Jabhat Al Nusra, stands at 67,296, the observatory said.
As the conflict ploughs into its 10th year, more than half of Syria’s pre-war population have been forced from their homes, and 80 per cent live below the poverty line.
With the economy destroyed and so many displaced, recovery remains a distant ideal as people struggle to reconcile the enormous losses sustained in a war that changes shape but seems impossible to end.