According to a recent report in The Wall Street Journal, Saudi Arabia, apparently with US backing, has agreed to provide advanced weaponry, including shoulder-fired anti-aircraft missiles, to a newly formed “Southern Front” of the Syrian rebellion under the leadership of Bashar al-Zoubi. Zoubi is the commander of the Yarmouk Brigade, a powerful rebel formation operating in the region of Daraa, near the Jordanian border. The choice to arm Zoubi and his fighters was reportedly made to the detriment of the Islamic Front, a coalition of rebel formations operating in the north, and on the assumption that the arms provided to the Southern Front would be less likely to “fall into the hands of al-Qaeda-inspired groups.”

If this is indeed the calculation of Washington and its regional allies, the problem with it is that Zoubi’s Yarmouk Brigade — like elements of the Islamic Front in the north — has been known to collaborate with none other than Jabhat al-Nusra. Jabhat al-Nusra is not merely “al-Qaeda-inspired.” It is the jihadist faction in Syria that is officially recognized as an al-Qaeda affiliate by al-Qaeda chief Ayman al-Zawahri. It was designated as a terrorist organization by the US State Department in December 2012.

In March 2013, the Syrian Observatory for Human Rights (SOHR) reported several joint operations by Jabhat al-Nusra and the Yarmouk Brigade, including, most notably, the storming of Syrian Air Defense Base 38 near the town of Saida. A summary of the SOHR report is available in English here.

Numerous videos posted to a YouTube channel bearing the Yarmouk Brigade logo document and celebrate the capture of Base 38. The videos and their accompanying titles essentially corroborate the SOHR account of the Yarmouk Brigade/Jabhat al-Nusra collaboration in the conquest of the base. The videos include statements from Zoubi from the site of the battle and grisly images of fallen "shabbiha" — Syrian Army soldiers— who are said to have been killed “at the hands of the heroes of the Free [Syrian] Army and Jabhat al-Nusra.” The massive and ghastly head wounds suffered by the victims suggest they were shot at close range, presumably executed.