It should be a point of interest as to why Assad would want to use chemical weapons when he was clearly already winning the war. The United States was remaining fairly uninvolved and Assad (knowing Obama had set out a "red line" concerning the chemical weapons) would bring about America's involvement by giving Obama the choice between acting on his word or facing complete humiliation at home and abroad. Assad would know that America's involvement would seriously undermine his efforts to take back control of his country.
Another consideration would be that the areas that are held by the Islamists and the FSA are said to be separated geographically and it was an FSA district that was supposedly hit with these chemical weapons. The Islamists are thought to be the more dangerous and formidable group that the Syrian military/government are fighting, so it would be stupid for Assad to attack the weaker group who would be easy to defeat using conventional weapons.
More logically, the Islamists wanted to force America's hand by crossing that "red line" and thus bringing them in to fight against Assad. There have been plenty of reports of them having confrontations with the FSA; this way, two birds could be killed with one stone.
Another consideration would be that the areas that are held by the Islamists and the FSA are said to be separated geographically and it was an FSA district that was supposedly hit with these chemical weapons. The Islamists are thought to be the more dangerous and formidable group that the Syrian military/government are fighting, so it would be stupid for Assad to attack the weaker group who would be easy to defeat using conventional weapons.
More logically, the Islamists wanted to force America's hand by crossing that "red line" and thus bringing them in to fight against Assad. There have been plenty of reports of them having confrontations with the FSA; this way, two birds could be killed with one stone.