Ahn Myong-Chol witnessed many horrors as a North Korean prison camp guard, but few haunt him like the image of guard dogs attacking schoolchildren and tearing them to pieces.

With stakes high and expectations low, Syria’s government and its opponents sit down face to face at an international peace conference this week for the first time – muscled to the negotiating table by foreign powers which fear the bloodiest of the Arab Spring uprisings may engulf the entire region in sectarian war.

Syria’s president Bashar Assad says his government will abide by the UN resolution calling for the country’s chemical weapons programme to be dismantled and destroyed.