The Hague: The fall of Syria's Bashar al-Assad, who has been implicated in using chemical weapons against his own citizens multiple times during the civil war, presents a significant opportunity to rid the country of these prohibited munitions, according to diplomatic sources.

The Organisation for the Prohibition of Chemical Weapons (OPCW) has been closely monitoring the situation in Syria, particularly chemical weapons sites, and has reiterated Syria's ongoing obligation to declare and eliminate all banned chemical weapons. Despite more than a decade of efforts, OPCW has made limited progress in uncovering the full extent of Syria's chemical weapons stockpile due to continuous obstruction from Assad's regime.

"Up until now, this effort has persisted, and Syria’s declaration of its chemical weapons program cannot be deemed accurate or complete," the OPCW stated. A diplomatic source revealed that Assad’s government had been elusive, playing a "cat and mouse" game with the OPCW for years, and they remain convinced that Syria continues its chemical weapons program. "This has cost millions with no significant progress," the source added. "Now, with the current situation, this is the best chance to eliminate these weapons once and for all."

However, before OPCW inspectors can be deployed, security arrangements must be made, potentially involving new power brokers in Syria, such as rebel forces that helped oust Assad, including Hayat Tahrir al-Sham, a former al-Qaeda affiliate. Previous missions have faced serious risks, such as attacks on UN-OPCW personnel in 2014.

Assad's government and its Russian allies have consistently denied using chemical weapons against opponents during the civil war, which began in 2011. However, three separate investigations—a joint U.N.-OPCW mechanism, the OPCW's Investigation and Identification team, and a U.N. war crimes investigation—have concluded that the Syrian government used sarin gas and chlorine-filled barrel bombs in attacks that killed or injured thousands.

A French court has even issued an arrest warrant for Assad, upheld on appeal, regarding the use of chemical weapons against civilians. U.S. Ambassador to the OPCW, Nicole Shampaine, highlighted that Syria’s undeclared chemical weapons remain a "proliferation risk" and expressed hope that recent developments in Syria would push the country toward fulfilling its international obligations.

Syria had initially declared 1,300 tons of banned chemical weapons when it joined the OPCW in 2013, and these were destroyed. However, inspections have uncovered evidence suggesting that Syria violated the 1997 Chemical Weapons Convention, with reports indicating that the chemical weapons program is ongoing. OPCW has held 28 rounds of consultations with Syria’s government, but discrepancies in their declarations continue to surface.

A recent assessment revealed 19 outstanding issues, including the potential undeclared development and production of chemical weapons at two declared chemical weapons-related facilities, as stated by OPCW chief Fernando Arias in November. Among the numerous victims of suspected chemical attacks are more than 1,000 people killed in the 2013 sarin gas attack in Ghouta, as well as around 100 killed in a gas attack on Khan Sheikhoun in 2017. The OPCW also found evidence of chlorine barrel bombs being used, resulting in many more casualties.