Blood and hair samples taken from victims after the attack confirmed that the lethal agent used was sarin gas — a toxic chemical that attacks a human’s nervous system, causing extreme respiratory distress that leads to coma and death, US President Barack Obama has said.
“The world saw thousands of videos, cellphone pictures and social media accounts from the attack, and humanitarian organizations told stories of hospitals packed with people who had symptoms of poison gas,” Obama said September 10 in a nationally televised address to the American people.
The United States, Britain and France, along with other allies, have collected information about the August 21 attack from international and Syrian medical personnel; videos; eyewitness accounts; thousands of social media reports from at least 12 different locations in the Damascus area; journalists’ accounts; and reports from credible nongovernmental organizations, according to a White House report based on a U.S. intelligence assessment that has been made public.
The US intelligence community concluded, based on an array of information and knowledge of Syrian military capabilities, that the regime of Bashar al-Assad carried out the poison gas attack against opposition-held elements in the Ghouta suburbs of Damascus, the White House said. “We assess that the scenario in which the opposition executed the attack on August 21 is highly unlikely,” the U.S. assessment said.
The Assad regime has been locked in a civil war with opposition forces since March 2011. More than 100,000 people have been killed in the ongoing civil conflict, which began when the Assad regime used the Syrian army to crack down on peaceful civilian protests, according to the United Nations.
Syria maintains the largest chemical weapons program and stockpile of agents in the Middle East — including mustard gas, sarin and VX — and has thousands of munitions that can be used to deliver chemical warfare agents, according to the U.S. assessment. It denied possessing any chemical weapons until the week of September 9, and it is one of only four nations that have not signed the international Chemical Weapons Convention.
In recent days, the Assad regime has announced it will seek to sign and ratify the Chemical Weapons Convention, following President Obama’s announcement that he was seeking authorization from the U.S. Congress to conduct a military strike against Syrian forces because of the chemical weapons attack.
According to unclassified intelligence reports, the Syrian Scientific Studies and Research Center (SSRC), which is subordinate to the Syrian Ministry of Defense, manages Syria’s expansive chemical weapons program. In testimony earlier in 2013, James Clapper, director of U.S. national intelligence, told Congress that Syria “remains dependent on foreign sources for key elements” of its chemical weapons program.
The mass of information gathered from multiple sources, the White House says, indicates the following sequence of events and actions by the Syrian army on August 21:
• Syrian chemical weapons personnel from the SSRC began preparing chemical munitions about three days before the early morning attack near an area that the regime uses to mix these weapons.
• Elements of the Syrian army in the area were issued protective gas masks just before the attack.
• Army units fired artillery and mortar shells into 11 neighborhoods that the Syrian military had been trying to clear of opposition forces by conventional means. Weather conditions contributed to the attack by creating atmospheric conditions that helped hold the deadly nerve gas close to the ground.
• The initial attack in the Damascus suburbs began at approximately 2:30 a.m. local time and ended about three hours later. The barrage was launched from regime-controlled areas and fired into opposition-controlled or contested neighborhoods.
• Three Damascus hospitals in the area closest to the attacks reported receiving approximately 3,600 patients displaying symptoms consistent with nerve agent poisoning in less than three hours.
• “The reported symptoms, and the epidemiological pattern of events — characterized by the massive influx of patients in a short period of time, the origin of patients, and the contamination of medical and first aid workers — were consistent with mass exposure to a nerve agent,” the U.S. assessment said, based on reports from international and Syrian medical personnel on the ground. Many medical and first responders to the chemical attack became ill as a result of exposure to contaminated patients.
• Videos and reported symptoms of victims were consistent with exposure to nerve agent poisoning and included unconsciousness, foaming from the nose and mouth, constricted pupils, rapid heartbeat and extreme difficulty breathing.
• Senior officials of the Assad regime reviewed the results of the initial attack, and increased shelling of the same neighborhoods in the days that followed, according to President Obama.
• Intercepted communications from a senior Syrian official familiar with the offensive confirmed that chemical weapons were used by the regime on August 21, and he expressed concern that the U.N. weapons inspectors might obtain evidence.
• On the afternoon of August 21, Syrian chemical weapons personnel were directed by the leadership to halt operations.
• In the ensuing days, the Syrian army intensified its conventional artillery and mortar barrage in the neighborhoods until the morning of August 26.
According to senior U.S. administration officials, there is high confidence in the full intelligence assessment, parts of which are still classified, that a chemical weapons attack occurred and that the Assad regime was responsible. The senior administration officials also said there is ample evidence that the Assad regime has used chemical weapons in the past, though on a much smaller scale.
