A woman affected by what activists say was a gas attack, breathes through an oxygen mask at a field hospital in Kfar Zeita village in the central province of Hama, Syria, April 12, 2014. Reuters
A woman affected by what activists say was a gas attack, breathes through an oxygen mask at a field hospital in Kfar Zeita village in the central province of Hama, Syria, April 12, 2014. Reuters

What it takes to stop the use of chemical weapons