Rival U.S. and Russian resolutions to extend the mandate of experts trying to determine who was responsible for chemical attacks in Syria were defeated Thursday at a heated Security Council meeting that reflected the deteriorating relations between Washington and Moscow.

The result of the two votes meant that the expert body — the Joint Investigative Mechanism (JIM) — would cease operations when its current mandate expires at midnight Thursday.

The U.S., its allies and human rights groups called it a serious blow to efforts to hold accountable those responsible for carrying out chemical weapons attacks in Syria.

During a three-hour drama, Russia first vetoed the U.S. draft resolution which was supported by 11 of the 15 Security Council members. Bolivia joined Russia in voting “no” and China and Egypt abstained.

Russia’s U.N. Ambassador Vassily Nebenzia withdrew the Russian resolution over Moscow’s insistence that it be voted on second not first as required under council rules. But using another council rule, Bolivia then resubmitted and called for a vote on that resolution. Continue reading.