Russian UN Ambassador Vitaly Churkin accused the US Monday of ignoring Moscow’s appeals for proof of Syrian government involvement in chemical weapons attacks on Syria. He spoke after a closed-door meeting on the UN chemical arms investigator Ake Sellstrom’s final report on the Aug. 21 sarin attack that killed 1,400 people. That report, said Churkin, was not persuasive. The investigation was not mandated to establish the source of the attack. He said Moscow viewed the incident as a rebel provocation. "Why would the opposition use chemical weapons? Exactly because of the red line [laid down by Obama and later recinded]: To provoke foreign military intervention in the Syrian conflict. It is absolutely obvious that on August 21 a large-scale provocation was staged."