Chemical Weapons Convention — international treaty banning chemical weapons
The CWC is the primary international treaty banning the development, production, stockpiling, and use of chemical weapons, with 193 states party as of 2022.
Key Facts
- Opened for signature
- 13 January 1993
- Entry into force
- 29 April 1997
- States parties (Aug 2022)
- 193 states
- Administering body
- Organisation for the Prohibition of Chemical Weapons (OPCW)
- Declared stockpiles destroyed
- All declared stockpiles irreversibly destroyed by July 2023
- Notable accession
- Syria acceded September 2013 as part of weapons destruction agreement
By the Numbers
Location
Cause → Event → Consequence
Widespread use and stockpiling of chemical weapons throughout the twentieth century, including in World War I and several Cold War-era conflicts, created international pressure for a binding multilateral agreement that would go beyond the earlier 1925 Geneva Protocol by mandating active destruction of existing stockpiles and establishing a verification regime.
The Chemical Weapons Convention was opened for signature on 13 January 1993 and entered into force on 29 April 1997. It prohibits the development, production, stockpiling, transfer, and use of chemical weapons and their precursors, and requires all member states to destroy existing stockpiles under verification by the OPCW, headquartered in The Hague.
The treaty brought 193 states into a binding disarmament regime; all declared chemical weapons stockpiles were irreversibly destroyed by July 2023. Notable milestones included Syria's accession in 2013 and the subsequent destruction of its declared arsenal, while the OPCW's verification mandate also provided a mechanism for investigating alleged use violations.
Political Outcome
International treaty entered into force; 193 states party; all declared chemical weapons stockpiles verified as destroyed by July 2023.
No binding multilateral ban with mandatory verification and destruction requirements for chemical weapons stockpiles
Global prohibition regime administered by OPCW, with systematic verification, destruction mandates, and investigation powers