Well before last month’s sarin nerve gas attack in a Damascus suburb, the Obama administration had gathered intelligence that chemical weapons had been used in Syria on multiple occasions but did not take action because there were debates about who was responsible and there was little public outcry, according to officials familiar with the intelligence.
A congressional official familiar with U.S. intelligence assessments told The Washington Times on Monday that evidence of the earlier attacks was what prompted senior administration officials to agree in June to a covert plan by the CIA to deliver small American arms to rebels in their fight against Syrian President Bashar Assad.
The official, who spoke only on the condition of anonymity because he was discussing sensitive assessments, added that there were two theories circulating in the intelligence community about why the August attack was much larger than the early deployments of chemical weapons.
“The working theory is the Assad regime had used chemical weapons on a small scale to gauge the international community’s reaction and since that reaction was limited, they felt they would be more comfortable in carrying out a larger-scale attack,” the source said. “The counterargument is that the Aug. 21 attack was actually meant to be smaller but they [expletive] up and used way more than they thought they were using.”
The revelation came as Paulo Pinheiro, chairman of the U.N. Commission of Inquiry on Syria, told reporters in Geneva that a team within the international body is investigating 14 incidents in which chemical weapons have — in at least some capacity — been used since the March 2011 breakout of Syria’s civil war.
Mr. Pinheiro’s disclosure raised fresh questions about what the Obama administration knew about the chemical weapons incidents in Syria before the larger-scale Aug. 21 attack that prompted President Obama to begin to demand airstrikes as a punishment against Mr. Assad.
It also sent a wave of political speculation through national security circles in Washington about the extent to which the administration deliberately may be avoiding confronting the issue, particularly in light of the so-called red line that Mr. Obama had set with regard to Syria’s chemical weapons.
At a news conference in August 2012, the president declared “that a red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilized. That would change my calculus. That would change my equation.”
On Monday, U.N. weapons inspectors released a long-awaited report concluding that the banned chemical sarin was used on a “relatively large scale” in last month’s attack on a Damascus suburb — an incident that U.N. Secretary-General Ban Ki-moon described as “the worst use of weapons of mass destruction in the 21st century.”
While the U.N. weapons inspectors did not ascribe blame for the attack, their report offered the first official scientific confirmation of the use of chemical weapons in Syria based on physical and biological samples from the scene of the attack. Western powers, including the U.S., France and Britain, have claimed in their own reports that there is a high degree of confidence that the attacks were carried out by Syrian military forces loyal to Mr. Assad.
But international observers have not said with total confidence who was behind previous uses of chemical weapons. “We are investigating 14 alleged cases of chemical weapons or chemical agent use. But we have not established the responsibility or the nature of the materials that were used,” Mr. Pinheiro told reporters in Geneva on Monday, according to Reuters.
One U.S. official told The Times on Monday that a general consensus exists among intelligence agencies about the number of previous incidents in Syria and noted that Mr. Pinheiro’s remarks dovetailed with an official British intelligence assessment that was made public Aug. 29.
The British report pinned the previous incidents on the Assad government. “We have assessed previously that the Syrian regime used lethal CW on 14 occasions from 2012,” it said, adding that “we think that there have been other attacks although we do not have the same degree of confidence in the evidence.”
A senior congressional source familiar with American intelligence assessments told The Times that among the 14 previous cases, there have been incidents in which “the intelligence could not clearly assess culpability, but in cases where it could be assessed, it’s always been the Assad regime that was deemed responsible.”
While the Russian government has claimed chemical weapons were used in Syria not by the Assad government, but by rebel forces fighting for the Syrian president’s ouster, the senior congressional source told The Times that: “I’ve never seen U.S.-generated reporting that has assessed that it was the rebels who used these things.”
Other sources in the intelligence community, who declined to comment on the record, suggested generally that the Obama administration may have been reluctant to aggressively respond to the previous incidents because they did not trigger the same level of global media attention generated by last month’s attack near Damascus.
The Obama administration has said more than 1,400 people, hundreds of them children, were killed in the attack, which was followed almost immediately by horrific videos, photos and witness accounts across social media facets of the Internet.
Some respected international organizations have concluded, however, that the prior incidents in Syria also involved the nerve agent sarin. In a posting on its website last week, Human Rights Watch said that “there is laboratory evidence that Sarin gas has been used in a previous attack in April on Jobar, near Damascus, when a photographer for Le Monde newspaper who was present at the time later tested for exposure to Sarin.”
The Obama administration was clearly aware of such reports. Roughly two months after the April incident, the White House released a statement attributed to deputy national security adviser Benjamin J. Rhodes, who said the U.S. intelligence agencies assess “that the Assad regime has used chemical weapons, including the nerve agent sarin, on a small scale against the opposition multiple times in the last year.”
“The intelligence community estimates that 100 to 150 people have died from detected chemical weapons attacks in Syria to date; however, casualty data is likely incomplete,” Mr. Rhodes said in the June 13 statement. “The President has been clear that the use of chemical weapons — or the transfer of chemical weapons to terrorist groups — is a red line for the United States.”
• Washington Times reporter Ashish Kumar Sen contributed to this article.