As UN inspectors were investigating claims that Sarin gas was used against civilians in Damascus, Lakhdar Brahimi, joint UN-Arab League envoy to Syria said, in a briefing to journalists: “It does seem clear that some kind of substance was used… that killed a lot of people” on 21 August.
But he also emphasised that any military action would need Security Council authorisation.
A UN diplomat confirmed that the permanent members of the UN Security Council will reconvene in New York today at 14:30 local time (17:30 GMT).
Here are examples of interventions that did pass through the Security Council:
Iraq 1991: US-led global military coalition, anchored in international law; explicit mandate from UN Security Council to evict Iraqi forces from Kuwait
Balkans 1990s: US arms supplied to anti-Serb resistance in Croatia and Bosnia in defiance of UN-mandated embargo; later US-led air campaign against Serb paramilitaries. In 1999, US jets provided bulk of 38,000 Nato sorties against Serbia to prevent massacres in Kosovo – legally controversial with UN Security Council resolutions linked to “enforcement measures”
Somalia 1992-93: UN Security Council authorised creation of international force with aim of facilitating humanitarian supplies as Somali state failed. Gradual US military involvement without clear objective culminated in Black Hawk Down disaster in 1993. US troops pulled out
Libya 2011: France and UK sought UN Security Council authorisation for humanitarian operation in Benghazi in 2011. Russia and China abstained but did not veto resolution. Air offensive continued until fall of Gaddafi
(Source BBC News, http://www.bbc.co.uk/news/world-middle-east-23864124#TWEET870753)