Continued from page 1

Mr. al-Labwani, who has provided U.S. and British intelligence with information on the Assad regime’s use of chemical weapons, said he thinks Al Wahdat Al Khassah — the regime’s special forces — and the Republican Guard are responsible for the chemical weapons attacks.

Syrian opposition activists say it is hard to tell with certainty where the regime stores its chemical weapons.

“They used to store it in the mountains, but [Mr. Assad] has since spread the chemical weapons all over,” said Mr. al-Labwani. He said the regime has mobile “factories” to activate the chemical weapons.

Only a secret group of regime insiders is aware of the location of the regime’s chemical weapons. “Even the people in the [Syrian government] ministries don’t know who these people are or where the chemicals are mixed,” said Sami Ibrahim, a Damascus-based spokesman for the Syrian Network for Human Rights.

Mr. Ibrahim said that besides the Aug. 21 attack a series of chemical attacks of lesser degrees of lethality have taken place across Syria, including in the cities of Homs, Aleppo and Idlib. “This indicates that there is a centralized command” behind these attacks, said Mr. Ibrahim.

Syrian opposition sources say the regime used napalm or a napalm-like substance to attack civilians in Aleppo on Monday.

Assad could have stopped these attacks after the first attack, but this gives a clear indication that there is a green light from the regime,” said Mr. Ibrahim.

Did the order for the Aug. 21 attack come from Mr. Assad?

“It’s probably more accurate to think of the regime as a sort of clique of various influential family as well as security actors,” said Faysal Itani, a fellow with the Atlantic Council’s Rafik Hariri Center for the Middle East. “So, even if it did not come from Assad himself, even though he is a sort of first among equals, then it still did come technically from the regime. This is a very tight-knit group of people. They don’t always agree about tactical issues but they do agree on broader strategic ones.”

Could the attack have been conducted without Mr. Assad’s knowledge?

“If that were the case it would indicate a very large breakdown in the chain of command on the Syrian government side,” said Elizabeth O’Bagy, a senior research analyst at the Institute for the Study of War. “The president has to approve the use of chemical weapons, either personally or through one of his official delegates. It is very unlikely that there were some sort of groups that were able to get their hands on chemical weapons who were able to launch the attacks without the senior-most leadership finding out about it.”

Western analysts and Syrian opposition activists are unable to say with certainty whether the Assad regime still controls its chemical weapons stockpiles, which include sarin gas, mustard gas and the nerve agent VX.

Jeremy Shapiro, a visiting scholar at the Brookings Institution, says its the regime’s responsibility to control these stockpiles.

“President Obama was very clear that it is the Syrian regime’s responsibility to maintain control over its chemical weapons, and if its lost control of its generals’ use of chemical weapons, that is just as bad, frankly,” said Mr. Shapiro.