A U.N. report detailing the scientific evidence behind the Aug. 21 chemical weapons attack in Syria carefully avoided laying blame for the incident. But the report’s details, particularly its calculations of the trajectories of the rockets that delivered poison gas to two Damascus suburbs, point directly at President Bashar Assad’s regime, experts concluded Tuesday after a day spent studying the U.N. findings.
Until this week, the public case against the Syrian government was based on trust in American, British and French assessments that were based largely on logic and conjecture but provided little detail about where information had come from. But the U.N. report, released Monday in New York, was filled with details gathered by inspectors from the Organization for the Prohibition of Chemical Weapons and was written with care so as to provide evidence without taking sides.
Specialists, however, said the report provided undeniable evidence that the rockets were launched from points outside the control of Syrian rebel fighters.
“If the U.N. inspectors correctly calculated the trajectories, it certainly seems to indicate that the chemically armed rockets were fired from government-controlled land,” said Peter Bouckaert, Human Rights Watch emergencies director and weapons expert. “It’s clear and convincing evidence.”
The key to that conclusion lies in the investigators’ determinations of the azimuths for the rockets they inspected. An azimuth is a way of indicating direction on a circle from any point. North is considered 0 degrees, south is 180 degrees. East is 90 degrees, west is 270 degrees. Variations of directions such as southeast or northwest are indicated by where they fall on the numbered circle.
The first attack that night was on the suburban enclave of Moadamiya, which is south of Damascus’ center. When studying the wreckage of two rockets and the craters they made, the inspection team determined that they’d come in at 34- and 35-degree azimuths, meaning they’d traveled from north-northeast to the south-southwest.
The second attack, about an hour or so later, left behind a crater and the ruins of a rocket in Zamalka, due east of Damascus. That rocket flew in at an azimuth of 285 degrees, meaning it had been traveling from west-northwest toward the east-southeast.
Lines drawn along those azimuths, taking into consideration the known maximum range of the rockets that hit Moadamiya and the estimated range of the rocket that hit Zamalka, intersect at the base of the 104th Brigade of Syria’s Republican Guard, on a hill overlooking central Damascus.
The base is adjacent to the Syrian Scientific Studies and Research Center, which is suspected of being the root of Syria’s chemical weapons program; the base itself is said to be home to Syria’s chemical warriors.
Bouckaert added that the early rockets can’t definitively be shown to have come from the Republican Guard base. But their flight paths offer little, if any, ground on which rebels can operate, leaving little doubt as to who fired them. The trajectory includes the Republican Guard base, the presidential palace and grounds, at least one other military base and the edges of the government-controlled airport.
Austin Long, a security and weapons expert at Columbia University, said his back-of-an-envelope tabulations since the U.N. report came out indicated that the Republican Guard, which is thought to control the chemical stockpiles, very likely moved one rocket system to a secure location near the base and launched.
“Then they could scuttle back home,” Long said in an email.
The rocket used in the second attack, he wrote, was unusual and more difficult to assess but most probably was fired from close to the base.
“The 330 mm rocket appears to be a unique Syrian weapon so I have not the foggiest idea of its range,” Long wrote. He added: “Just eyeballing the map and knowing the azimuth, the two attacks could have very similar points of origin.”
Azimuths weren’t the only evidence damning the Syrian regime in this case. Bouckaert noted that the weapons and the attack itself implicated the Syrian military. The rebels are known to have launchers for rockets similar to the ones that hit Moadamiya, but theirs are smaller versions with 120 mm rockets, not 140 mm rockets as used in the attack.
The reason is clear, Bouckaert said: The 140 mm version is an outdated piece of Soviet hardware, and was designed for chemical attacks. The overall usefulness of such a weapons system to the rebels, even if they had chemicals to use, would be limited.
The rocket that hit Zamalka, however, is stronger evidence. Bouckaert said the 330 mm rocket was made industrially.
“But we haven’t seen it before in any conflict,” he said. “It’s not in the books. It’s not listed anywhere.”
It appears to have been designed to be fired from an Iranian launcher, which the Syrians are known to have. But the rocket itself appears to be Syrian made.
“The 140 mm rockets carry about 5 liters of sarin liquid, which vaporizes on impact,” he said. “But the 330 mm rocket is essentially a rocket with a trash can on the end. It carries about 55 liters of sarin liquid, which also vaporizes on impact.”
He said Human Rights Watch estimated that far more people died from the 330 mm shelling.
“Two different rocket systems, both known to be used by the Syrian regime and not by the rebels, a precision attack on rebel areas, a substantial amount of sarin and launched from regime-controlled areas,” Bouckaert said, rattling off the clues to the Assad regime’s involvement. “The case is very strong.”