Chemical weapons program of Syria
Syria's chemical weapons program began in the 1970s with weapons and training from Egypt and the Soviet Union, with production of chemical weapons in Syria beginning in the mid-1980s. For some time, Syria was believed to have the world's third-largest stockpile of chemical weapons, after the United States and Russia. Prior to September 2013 Syria had not publicly admitted to possessing chemical weapons, although Western intelligence services believed it to hold one of the world's largest stockpiles. In September 2013, French intelligence put the Syrian stockpile at 1,000 tonnes, including Yperite, VX and "several hundred tonnes of sarin". At the time, Syria was one of a handful of states which had not ratified the Chemical Weapons Convention. In September 2013, Syria joined the CWC (formally acceding on 14 October), and agreed to the destruction of its weapons, to be supervised by the Organisation for the Prohibition of Chemical Weapons (OPCW), as required by the convention. A joint OPCW-United Nations mission was established to oversee the destruction process. Syria joined OPCW after international condemnation of the August 2013 Ghouta chemical attack, for which Western states held the Syrian government responsible (whilst Syria and Russia held the Syrian rebels of the Syrian civil war responsible) and agreed to the prompt destruction of its chemical weapons. 
The destruction of Syria's chemical weapons that the Assad government had declared was completed by August 2014, yet further disclosures, incomplete documentation, and allegations of withholding part of Syria's chemical weapons stockpile since mean that serious concerns regarding chemical weapons and related sites in Syria remain. On 5 April 2017, the government of Syria allegedly unleashed a chemical attack that killed 70 civilians. A suspected chemical attack on Douma on 9 April 2018 that killed at least 49 civilians has been blamed on the Syrian Government.
As of the Fall of the Assad regime in December 2024, Syria retained at least some chemical weapons, whose status was thrown into flux with the sudden shift in the Syrian tactical situation.
Overview.
Public stance.
Prior to entry into force on 14 October 2013 of Syria's instrument accession, Syria was one of five states that had not signed and seven that had not ratified the Chemical Weapons Convention, which prohibits the development, production, stockpiling, transfer, and use of chemical weapons. However, in 1968, Syria acceded to the 1925 Geneva Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or Other Gases. Syria had repeatedly pledged to ratify the CWC if its neighbouring countries, especially Israel, ratify the convention. In the aftermath of the 2003 invasion of Iraq, Syria stated that it had no chemical weapons, but stated it possessed such weapons in 2012. The Syrian president had earlier alluded to a chemical weapon capability in public statements, in 1990 and 1997.
Western non-governmental organisations stated they believed Syria had an active chemical weapons program.
In September 2013, Syria provided information about its stockpile to the OPCW as part of its disarmament obligations. However, the exact composition of its declared chemical arsenal will not be disclosed to the public, due to OPCW rules.
Motivation.
A number of reasons have been postulated for Syria's adoption of a chemical weapon strategy in the 1980s:
Stockpiling and production.
According to some US analysts, Syria was provided with some chemical weapons and delivery systems prior to the 1973 Yom Kippur War. According to US intelligence reports, Syria began to develop its chemical weapons capabilities in the later 1970s, with supplies and training from the Soviet Union, and likely with equipment and precursor chemicals from private companies in Western Europe. However Syrian production of chemical weapons is not believed to have begun until the mid-1980s. The Director of the US Defense Intelligence Agency said in 2013 that the Syrian program had never become fully independent, and remained reliant on the importing of precursor chemicals.
In 1988, a U.S. analyst described Syria's chemical weapon capability as more advanced than the Iraqi chemical weapons program; however, Israel stated in 1989 that Syria had only the "potential for chemical warfare, but not more than that". In the meantime, a Syrian chemical weapons scientist, dubbed as "the chemist" who was recruited by the CIA from 1988 until his execution in 2001, reported that there was a lab known as "Institute 3,000" near Damascus to manufacture chemical weapons, as later revealed in Joby Warrick's "Red Line" book.
In July 2007, a Syrian arms depot exploded, killing at least 15 Syrians, as well as 10 Iranians. Jane's Defence Weekly, a U.S. magazine reporting on military and corporate affairs, believed that the explosion happened when Iranian and Syrian military personnel attempted to fit a Scud missile with a mustard gas warhead. Syria stated that the blast was accidental and not chemical related.
Capabilities in 2013.
A 2007 assessment indicated that Syria was capable of producing several hundred tons of chemical weapon agents per year. Another 2007 report said that Syria was believed to have a stockpile of hundreds of tonnes of chemical weapons agents. Syria was believed to be able to deliver chemical weapons by aerial bombs, surface-to-surface missiles and artillery rockets.
In September 2013, a French intelligence report put the Syrian stockpile at over 1,000 tonnes, including nerve agents and their precursors. This included several hundred tons of Yperite, several hundred tons of sarin, and tens of tons of VX. The report stated that Syria uses a "binary form" technique which demonstrates that Syria has acquired "great knowledge" of chemical weapon technology. As delivery systems the report highlighted as longer-range systems Scud B and Scud C missiles, with a range of 300 and 500 km respectively; and the M-600 (a Syrian version of the Iranian Fateh-110) with a range of 250–300 km. Shorter-range systems include SS21 missiles (70 km); aerial bombs; and artillery rockets and related short-range tactical systems (50 km or less). As of October 2013, some experts believe Syria has around 300 metric tonnes of sulphur mustard and around 700 metric tonnes of nerve agents. By the end of October 2013, the OPCW found a total of 1,300 metric tons of chemical weapons.
According to French intelligence, the Syrian Scientific Studies and Research Centre (SSRC) is responsible for producing toxic agents for use in war. A group named "Branch 450" is allegedly responsible for filling munitions with chemicals and maintaining security of the chemical agent stockpiles.
To provide context for these estimates, 190,000 tons of chemical weapons were manufactured by World War I combatants.
Facilities.
Syrian chemical weapons production facilities have been identified by Western nonproliferation experts at approximately 5 sites, plus one suspected weapons base:
Destruction.
Following the Ghouta attacks, Secretary-General of the United Nations Ban Ki-moon suggested that he might request that the United Nations Security Council vote to demand that Syria ratify the CWC. On 10 September 2013, Syria announced its intention to join the chemical weapons convention, following a Russian proposal to assist Syria with disposing of their chemical arsenal, and subsequently submitted an instrument of accession to the United Nations as the depositary. Syria formally acceded to the CWC on 14 September 2013, with the convention coming into force for Syria 30 days after their deposit of the instrument of accession on 14 October 2013. In a telephone call with the Organisation for the Prohibition of Chemical Weapons (OPCW) director-general, Syrian Deputy Minister Faisal Mekdad asked for technical assistance and requested that the CWC be provisionally in force prior to its formal entry in force. The OPCW announced that this request had been circulated with its member states.
On 14 September 2013, the United States and Russia announced that they had agreed to a disarmament framework that would eliminate Syria's chemical weapons programs. Under this framework: 
On 27 September 2013, the OPCW agreed on an accelerated program for eliminating Syria's chemical weapons by mid-2014, consistent with this framework. On 16 October 2013, an OPCW-UN Joint Mission was established to oversee this process. The destruction of Syria's chemical weapons was completed by August 2014.
Use.
Syrian civil war.
At the outbreak of civil war concerns were raised about both the security of Syria's chemical weapons sites and about the potential use of chemical weapons. In July 2012, Syrian Foreign Ministry spokesman Jihad Makdissi stated that "No chemical or biological weapons will ever be used... All of these types of weapons are in storage and under security and the direct supervision of the Syrian armed forces and will never be used unless Syria is exposed to external aggression."
A Syrian defector who worked inside the chemical weapons network alleged that in January 2012 two senior Syrian officers moved about 100 kg. of chemical weapons materials from a secret military base in Nasiriyah. The Syrian source also described construction of special trucks, which could transport and mix the weapons. These mobile mixers were constructed inside Mercedes or Volvo trucks that were similar to refrigerator trucks. Inside were storage tanks, pipes and a motor to drive the mixing machinery, the defector said.
In September 2012, the Syrian military began moving its chemical weapons from Damascus to the port city of Tartus. That same month, it was reported that the military had restarted testing of chemical weapons at a base on the outskirts of Aleppo. On 28 September, US Defence Secretary Leon Panetta stated that the Syrian government had moved its chemical weapons in order to secure them from approaching opposition forces. It emerged that the Russian government had helped set up communications between the United States and Syria regarding the status of Syria's chemical weapons. Russian Foreign Minister Sergei Lavrov stated that Syria had given the United States "explanations" and "assurances" that it was taking care of the weapons. On 8 December, it was reported that members of the jihadist Al-Nusra Front had recently captured a Saudi-owned toxic chemicals plant outside of Aleppo. On 22 December 2012, Russian Foreign Minister Sergei Lavrov stated that Syria had consolidated chemical weapons into one or two places to prevent rebels capturing them, and that recent moves that had alarmed Western governments were part of this consolidation. Brigadier General Mustafa al-Sheikh, a Syrian army defector, confirmed that most of the chemical weapons have been transported to Alawite areas in Latakia and near the coast. Some chemical munitions remain in bases around Damascus. In December 2012 McClatchy reported various chemical weapons experts' scepticism that Syria was preparing to use chemical weapons, noting their "limited utility" in a civil war situation with fluid battle lines, and Syria's comments that such use would be "suicide" in view of US threats of retaliation.
Incidents.
On 23 December 2012, Al Jazeera released unconfirmed reports that a gas attack killed 7 civilians in the rebel-held al-Bayyada neighbourhood of Homs. Some American officials felt there was a "compelling case" the government forces had used Agent 15, but the White House was initially sceptical.
On 19 March 2013, unconfirmed reports surfaced, after initial reports on the Syrian state news agency SANA, that missiles armed with "chemical materials" may have been fired into the Khan al-Asal district in Aleppo and the Al Atebeh suburbs of Damascus. At the time of the attack, Al Atebeh was held by the opposition. Government forces controlled much of the village of Khan al-Asal; opposition forces held much of the remainder of Aleppo, including areas surrounding Khan al-Asal. Both sides accused each other of carrying out the attack. The Syrian Observatory for Human Rights said that 16 government soldiers and 10 civilians had been killed in the Khan al-Assal chemical attack after a rocket landed on Khan al-Assal, about 300 meters from a military checkpoint. Activists said that the government had tried to hit the rebel-held police academy with a Scud missile, but the missile accidentally landed in a government-controlled area instead. An unnamed Reuters photographer described the gas as having a "chlorine-like smell" and claimed to have witnessed victims suffocating. Officials from within the United States government disputed this claim and stated that there had been no substantive evidence of chemical warfare in Syria, while, the Russian government indicated that it was taking the Syrian government's claim seriously. Unusually, Syria requested that the UN send inspectors to investigate.
In April 2013 Zahir al-Sakit or al-Sakat, a former Syrian army general from the chemical weapons branch, said he had been instructed to use chemical weapons in caves and tunnels that are used by the FSA, during battles in the southwestern area of Hauran. But instead, Sakit disobeyed the orders and swapped the chemicals with