British Foreign Secretary William Hague said on Saturday said that there is evidence that the Syrian government could use its chemical weapons stocks in its conflict with rebels fighting to oust it.

“We are extremely concerned about the stockpiles of chemical and biological weapons, and we are also concerned about evidence during the last couple of weeks that the regime could use them,” Hague told reporters in Manama on the sidelines of a regional security conference.

Senior U.S. defense officials are drafting plans for a potential preemptive strike against government forces loyal to Syrian President Bashar Assad, prompted by concerns over the country's chemical weapon stockpiles.

While information on the specific status of those weapons remains extremely fluid, recent U.S. intelligence showed Assad's forces outfitting air-to-ground bombs with sarin gas at two airfields in Syria, according to CNN.

Syrian rebel groups meeting in Turkey elected a 30-member unified command on Friday at talks attended by security officials from international powers, delegates said.

The 30 included many with ties to the Muslim Brotherhood and Salafists, and excluded the most senior officers who had defected from President Bashar al-Assad's military, they said.

The Foreign Secretary said on Saturay that he had seen intelligence reports that Damascus was assembling chemical and biological stockpiles as a last-ditch defence against the growing rebel onslaught.

Syria warned the United Nations on Saturday that rebels may employ chemical weapons after they gained control of a factory producing toxic chlorine east of Aleppo city.

While it is true that the Obama administration may intervene under scenario (1), public statements to this effect are misleading. Consider Bilal Y. Saab, Executive Director of the Institute for Near East and Gulf Military Analysis, on why Obama’s supposed red line on the use of chemical weapons “lacks credibility.”