Spreading sectarian conflict 'most probable' scenario in Syria says US ambassador to UN

At that point, she said, the Annan plan would be dead and “this becomes a proxy conflict, with arms flowing in from all sides and members of this council – and members of the international community – are left with the option only of having to consider whether they're prepared to take actions outside of the Annan plan and the authority of this council.”

Rice's comments were aimed at the Syrian government and members of the Security Council, particularly Russia, which she said must remain united in raising pressure on Syria.

“If we don't,” Rice said, “then we are all resigning ourselves to [the] third scenario.”