# Chemical Weapons Convention The Chemical Weapons Convention entered into force in 1997 and is the most successful disarmament treaty ever concluded. It bans the development, production, stockpiling, transfer and use of chemical weapons, requires destruction of existing stockpiles, and — uniquely among WMD regimes — created a permanent implementing body with **routine and challenge inspection powers**: the Organisation for the Prohibition of Chemical Weapons, in The Hague. **193 states parties.** All declared stockpiles have been destroyed, including the American stockpile, completed in 2023. That record is the reason this page belongs in the vault. When the [[Biological Weapons Convention]] page describes what a treaty without verification looks like, the CWC is the comparison. ## Syria — The Test Case [[Syria]] acceded under duress in 2013, after the Ghouta sarin attack, in a deal that averted US strikes. Its declaration was never credible; the OPCW said so repeatedly from 2014. Syria's rights and privileges under the Convention were **suspended in 2021**. Then the government fell, and inspectors got access. **27 May 2026** — an OPCW expert team deployed to Hama, Homs and Latakia and **found chemical weapons that had never been declared**: dozens of munitions and aerial bombs matching those used at Ltamenah and Khan Shaykhun in 2017, rockets **identical to those used in the August 2013 Ghouta attack**, plus chemicals, equipment, and thousands of pages of documentation. The Secretariat has now identified **more than 100 locations** potentially relevant to the programme. Director-General Fernando Arias said the find "confirms the Secretariat's repeated assessment since 2014 that the former Syrian regime withheld information and unsuccessfully attempted to mislead the Secretariat." **9 July 2026** — the Executive Council **reinstated Syria's rights and privileges**, co-sponsored by 67 states parties and adopted by consensus, alongside a verification plan for destroying remaining munitions at Al Qutayfah. Both facts are true at once: the organization confirmed a decade of deception, and restored the successor government's standing so that destruction could proceed. That is what a functioning verification regime looks like — not the absence of cheating, but the eventual documentation of it. ## Russia and Ukraine The OPCW has conducted **three Technical Assistance Visits** to Ukraine, reporting in November 2024, February 2025 and June 2025. The November 2024 visit **found the riot-control agent CS in samples**, and the OPCW confirmed likely RCA use — which the Convention prohibits as a method of warfare. The separate and more serious **chloropicrin** allegation originates in a **US State Department determination of May 2024** that Russia used it against Ukrainian forces in violation of the Convention. Russia counter-alleges Ukrainian use and complains the OPCW has not responded; that claim comes via Russian state media and should be treated as a claim. The next Conference of States Parties, **CSP-31, meets 23–27 November 2026** in The Hague. ## Why It Matters Here The CWC is the control case for the vault's whole treaty layer, and it cuts against the pessimistic reading. Every other page in this cluster documents an instrument being narrowed, exited, defunded, or allowed to lapse. The CWC has near-universal membership, destroyed every declared stockpile including America's, and in 2026 sent inspectors into a country that had lied to it for a decade and produced the documentation. It did that while the United States was exiting 66 international bodies. Two features explain the difference, and both are worth carrying to the other pages. First, **it has intrusive verification** — routine inspections plus a challenge mechanism — which the [[Biological Weapons Convention]] does not, and which the [[Nuclear Non-Proliferation Treaty]] has only through the IAEA and only for non-nuclear states. Second, **no great power's core strategic capability depends on violating it.** Chemical weapons are militarily marginal for states that possess nuclear ones. Compliance is cheap. That is the uncomfortable lesson. The treaties that work are the ones that verify and that nobody powerful badly wants to break. It does not tell you much about whether the [[New START]] problem was solvable — but it does establish that the failures documented elsewhere in this cluster are not evidence that treaties can never work. > [!note] Not verified > I could not confirm any specific US funding action, arrears, or contribution change affecting the OPCW in 2025–26, nor a distinct US statement at the November 2025 Conference of States Parties. ## See Also - [[Biological Weapons Convention]] — the same idea without verification - [[Nuclear Non-Proliferation Treaty]] — the WMD regime with the hardest politics - [[Convention on Cluster Munitions]] · [[Ottawa Mine Ban Convention]] — the humanitarian-disarmament track - [[International Criminal Court]] — where chemical-weapons use can become individual liability - [[Russo-Ukrainian War]] - [[International Law Hub]]