The Washington Post reports: A chemical attack that killed scores of civilians in Syria likely involved a banned nerve agent, top medical groups concluded Wednesday, as the United States and European allies at the U.N. Security Council demanded a full investigation.

But denunciations at the United Nations faced strong obstacles from Russia, a critical ally of Syria’s government.

Before the Security Council’s emergency session, Russia broke with global consensus that blamed Tuesday’s attack on the Syrian regime and instead claimed it was carried out by Syrian rebel groups. A rebel commander called Russia’s assertion “a lie.”

The Russian stance underscored the difficulties of seeking greater international pressure on the government of Bashar al-Assad as it escalates an air campaign against the remaining anti-government strongholds in northern Syria. [Continue reading…]