Prepared by James Lewis with invaluable support from Philip Coyle
What is sarin?
Simple explanation: Sarin is a nerve agent that restricts breathing and other vital functions. It affects the biological mechanism that makes muscles contract and stop contracting.
For Bill Nye fans: Sarin is an organophosphate, a molecule containing a phosphorus atom double bonded to an oxygen atom and also bonded to a carbon-containing group. Organophosphates were originally developed as insecticides.
Nerve agents like sarin and VX are irreversible acetylcholinesterase inhibitors. Acetylcholinesterase hydrolyzes acetylcholine, a neurotransmitter. Acetylcholine is used by the nervous system to tell muscles when to contract or “fire.” Acetylcholinesterase breaks down acetylcholine and nerve agents inhibit this function. If acetylcholine is not broken down, it will continue to tell muscles to fire.
How much sarin does Syria have?
The exact size of Syria’s chemical arsenal is unknown. However, Syria is the largest holder of chemical weapons in the Middle East and the fourth-largest global holder of chemical weapons. According to Laicie Heeley, our Middle East and Defense Policy Director, Assad’s sarin arsenal is estimated to be in the high hundreds of tons, possibly more than 1,000 tons.
How do we think sarin was used?
Different U.S. intelligence agencies have varying degrees of confidence that chemical weapons were used. Evidence of chemical weapons usage comes from physiologic samples; sarin is a complex organophosphate that leaves specific trace chemicals in the blood stream of poisoning victims. The intelligence estimate is also based on symptomatic evidence of victims and human intelligence.
The President reported the evidence of chemical weapons usage to the relevant Congressional committees in a letter dated April 25th.
U.S. intelligence continues to investigate the situation because the chain of custody for the biological samples is still unclear. Additionally, the U.S. has called for a U.N. investigation.
The governments of France and the United Kingdom have reported evidence of chemical weapons use to the U.N. Security Council.
How do we know who used nerve agents in Syria?
At present, U.S. intelligence has not confirmed that President Assad or the Syrian government ordered the use of nerve agents. It is expected that forthcoming intelligence/investigations will combine human intelligence with physiological test results to create a clearer picture of the events in Syria.
U.S. intelligence does believe that all of Syria’s chemical weapons are still under the control of the Assad government, however Assad has refused sufficient UN weapons inspector access to his chemical weapons facilities.
Some experts have suggested that chemical weapons may have been used without the knowledge of President Assad or that Syrian rebels tainted the blood to incite an American response.
Has anyone else used sarin?
Sarin was likely used during the Iran-Iraq War and Saddam Hussein also used it against Iraqi Kurds as a weapon of genocide. It is estimated the act conducted with sarin and mustard gas killed 5,000 and permanently injured 65,000.
The Japanese religious sect, Aum Shinrikyo, released sarin on the Tokyo Metro in 1995 killing thirteen people and sickening hundreds; they had previously attempted to use it in 1994 but failed.
Are nerve agents an effective weapon?
In the current Syrian situation, chemical weapons are really a terror weapon. People start to twitch and foam at the mouth, and can die without bullet holes, cuts or blood.
The type of urban warfare occurring in Syria is not particularly conducive to the use of chemical weapons, unless individuals are within a contained space, like a building. Sarin could effectively be pumped through the ventilation system of a building. The Russians used a chemical incapacitant on a group of Chechen terrorist and hostages on October 26, 2002 at the Dubrovka theatre in Moscow. The agent is still considered a State secret but was likely an opioid compound.
If Assad used chemical weapons, it is a dangerous game for him. President Obama has said that the use of chemical weapons would change the US’s political and decision-making calculus. Additionally, chemical agents are difficult to control and could be “blown back” on friendly troops if weather patterns are not taken into account.
What does the use of a chemical weapon mean for global non-proliferation?
The use of any weapon of mass destruction undermines the global goal of preventing the proliferation and use of these weapons.
The UN Security Council has classified sarin as a weapon of mass destruction and the Chemical Weapons Convention lists it as a Schedule 1 substance (the most dangerous). Syria is not party to the Chemical Weapons Convention but nearly all of the global community is party to the Convention which establishes a global norm against the use of chemical weapons.
Syria will continue to be a threat to global non-proliferation efforts until it disarms its chemical arsenal.