Over a week after a horrific chemical attack killed dozens of people in the Syrian town of Douma, the Associated Press reports that inspectors have arrived in the country to investigate the details of the April 7 attack.
While the United States, France, and the United Kingdom all say the Syrian government of Bashar al-Assad is to blame for the attack. Meanwhile, Russia, Assad’s ally, has called the attack a hoax and, along with Syria, had thus far blocked the Organization for the Prohibition of Chemical Weapons (OPCW) inspectors from entering Douma. The town has been besieged as the government has been fighting to oust rebels from the greater eastern Ghouta region, just outside the capital of Damascus.
The United States led a series of strikes on three facilities associated with chemical weapons in Syria on Friday night in retaliation for the chemical attack, with the Kremlin alleging that the United States and its allies violated international law in carrying out the strikes.
What an OPCW inspection can do
An inspection by the team of experts can definitely prove whether a chemical weapon has been used, but not who used it.
“Investigating culpability for chemical weapons use is not a question of ability, but rather of authorization.The OPCW Fact-Finding Mission is tasked only with investigating if an alleged chemical weapons attack took place and if so, what kind of chemical weapon was used,” said Alicia Sanders-Zakre, policy and programs research assistant at the Arms Control Association.
Sanders-Zakre told ThinkProgress that joint investigations with the U.N. have a wider mandate.
“The U.N.-OPCW Joint Investigative Mechanism (JIM), however, which was shut down because of a Russian veto at the UN Security Council in November, was authorized to investigate the responsible actor for chemical weapons attacks in Syria,” she said.
“It found the Syrian government responsible for chemical weapons attacks on four occasions and the Islamic State guilty of chemical weapons use in two instances. Of course, each actor is likely guilty of many more attacks,” added Sanders-Zakre, noting that Nikki Haley, the U.S. ambassador to the U.N. on Friday accused Syria of carrying out over 50 chemical attacks since the start of the Syrian conflict.
It can also determine what kind of agents were used via samples taken from those exposed as well as their surroundings. They will interview witnesses and medical staff.
The United States has raised concerns that Russia might have tampered with evidence on the scene — a charge Russia vehemently denies — and it remains to be seen what investigators will find and what they’ll have access to.
Russia, for its part, insists that its own specialists have found no trace of a chemical attack.
Ralf Trapp, international disarmament consultant and former OPCW officer told ThinkProgress that what investigators find depends on what was used and how much was retained and absorbed by materials at the impact site.
“Cleaning up a site after a chemical attack to the point where no traces of the agent or of characteristic degradation products can be found is difficult, in particular when the impact site was a building. And even if there was decontamination/clean-up, the signs of that clean-up operation will still be detectable,” said Trapp.
But access to the victims, the medical staff who treated them, and all relevant medical records and documents is “the responsibility of the country hosting the investigation,” noted Trapp.
Additionally, patients would have to give consent for urine and blood samples to be taken and analyzed.
What an OPCW inspection can’t do
Given that 11 days have passed since the attack, some chemicals might be harder to trace. A chlorine attack, for instance, will be harder to trace in those exposed, as it does not tend to stay in the body for long and tends to break down and dissipate pretty quickly.
“Detection would be more difficult in case of agents such as chlorine — a gas that would dissipate rapidly with the air, and also there is a natural background for chlorine in the environment,” said Trapp, “but even in such cases there may still be chemical reaction products of the agent and materials of the local environment that can be found in concentrations that are higher than would normally be expected, and that could give indirect hints at whether a chemical agent had been used.”
Even if they find that weapons have been used, the inspectors can’t say who deployed them. In past chemical attacks in Syria, non-state actors, such as the self-proclaimed Islamic State (ISIS) and other rebels groups, have been suspected of using chemical weapons on civilians.
Syria joined the Chemical Weapons Convention in 2013, but violated it repeatedly since then.
Also, it’s worth noting that no matter which party is found to have been blamed for the deaths in Douma, that so far, neither sanctions nor missile strikes have prevented the use of chemical weapons in the war.
Additionally, while the use of chemical weapons is prohibited and presents a rather vague red line for some Western leaders — notably, President Donald Trump — far more people have died via conventional weapons and warfare in Syria since the start of the unrest there in 2011, resulting in over half a million deaths and the displacement of millions.