By Daryl G. Kimball, Greg Thielmann, and Kelsey Davenport
The U.S. intelligence community "assesses with varying degrees of confidence, that the Syrian regime has used chemical weapons on a small scale in Syria, specifically, the chemical agent sarin," according to information released by the White House on April 25 in a letter to Senators Levin and McCain.
The U.S. allegations follow letters written to the UN Secretary General by both France and the United Kingdom, and public allegations by Israel, that chemical weapons have been used in the Syrian civil war on multiple occasions since December 2012.
Despite the mounting evidence, it is important to emphasize that the U.S. assessment of chemical weapons use is not yet definitive. The April 25 letter said that the "chain of custody is not clear" making it difficult to determine how the exposure occurred and "under what conditions."
This assessment increases the urgency of empowering the Organization for the Prohibition of Chemical Weapons (OPCW) to thoroughly investigate the very serious possibility that the Syrian government has authorized the use of internationally banned chemical weapons against its own people.
Now, the international community must unite in efforts to achieve a full investigation of the evidence. In particular, the UN Security Council should meet to outline a course of action to prevent any further use of chemical weapons, including ensuring that the Syrian Government permits and facilitates access by the team the UN Secretary General has called on to conduct the investigation.
Despite having requested that UN investigate a possible chemical weapons attack that took place on March 19, Syria is currently refusing to allow inspectors to enter the country, unless the UN agrees to confine its investigations to that single incident.
All states, particularly Syrian allies such as Russia and Iran, should urge Syrian strongman Bashir al Assad to allow the UN investigation into the past use of chemical weapons to go forward unhindered and reiterate that the use of chemical weapons by any party in the Syrian conflict is unacceptable and individuals involved will be held accountable. Iran, as a victim of massive Iraqi chemical attacks in the past, has a particular responsibility to condemn chemical weapons use.
The United States and the international community must take the allegations of chemical weapons use seriously and step up efforts to investigate these allegations and pressure the regime to allow UN inspectors unfettered access to Syria.
However, any military intervention must be carefully considered. Such an intervention would not necessarily prevent further use of chemical weapons. In fact, it could increase the chances that Assad will follow through on his threat to use chemical weapons more broadly or cause the military conflict to spread into neighboring countries.