Syria’s sorrow

The images from Ghouta outside Damascus this week, showing row after row of corpses of men, women and children, none with visible signs of injury, were among the most shocking to have emerged from Syria's brutal civil war, which has left 100,000 dead and millions more displaced. The assault, which left anywhere from five hundred to more than a thousand dead, bore the hallmarks of a chemical weapons attack, possibly involving the use of a nerve agent. Although United Nations weapons inspectors are currently in Syria to investigate earlier alleged chemical weapons attacks, they have so far been unable to gain access to Ghouta and there has been no independent verification of the nature of the incident. Russia, one of the most important allies of Bashar al Assad's regime, has joined western calls to allow the inspectors to visit the area, which is held by rebel forces.

This week's attack came a year after President Barack Obama declared that the use of chemical weapons would represent the crossing of a "red line" and a "game changer" in Syria that could trigger US action against Assad's regime. France's foreign minister, Laurent Fabius, said that the western powers should respond with force and Britain yesterday declined to rule out an armed response but Mr Obama warned yesterday that "jumping into stuff that does not turn out well" can result in costly, protracted military interventions that can breed more resentment in the region.

The options for military intervention in the conflict are complicated by divisions within the Syrian opposition, which includes radical Islamist elements hostile to the west and by opposition to such action from within the UN security council from Russia and China. External military intervention offers little hope of ending the stalemate in Syria and could further weaken fragile hopes of a negotiated agreement during peace talks planned for later this year.

The use of chemical weapons by either side in the conflict has important implications beyond Syria, however, in safeguarding a powerful example of collective self-restraint in international affairs that has endured for almost a century. The widespread use of poison gas and other chemical agents during the first World War killed more than 100,000 soldiers on both sides and disabled another million. Revulsion at the horrors caused by chemical weapons prompted most countries to sign a covenant in 1925 banning their use and most have abided by that agreement ever since. An exception came in 1988 when Saddam Hussein killed as many as five thousand civilians in a chemical attack on the Kurdish town of Hallabja in northern Iraq. The circumstances surrounding this week's atrocity should be established quickly and if it was indeed a chemical attack, the perpetrators must be held to account for their war crime.