Phil Sands and Suha Maayeh of The National add detail to what we have long known from sources: the Islamist faction Jabhat al-Nusra, designated a “terrorist organization” by the US Government, has long co-operated with other insurgent groups — even the US-backed Free Syrian Army.

The Islamic Front, the leading insurgent bloc, did not include Jabhat al-Nusra in its membership when it was launched in November; however, the Front has established an effective if discreet working relationship with JAN. Before that, most of the seven factions in the bloc had been involved with JAN on the battlefield.

Those operations had largely been in northern Syria, however, and Sands and Maayeh rightly note that JAN has been increasingly involved in battles in the south. The group has taken part in operations for several months. It was involved in September’s capture of a crossing on the Jordanian border near Daraa city, and only last week JAN suicide bombers were instrumental in the capture of the Jassim barracks in Daraa Province.

Sands and Maayeh build on their recent revelations about the FSA and the southern front, including a foreign-staffed “command center” working with the insurgency:

“They offer their services and cooperate with us, they are better armed than we are, they have suicide bombers and know how to make car bombs,” an FSA fighter explained….

Others admitted that Al Nusra’s role in fighting in southern Syria is far greater than publicly acknowledged.

“The FSA and Al Nusra join together for operations but they have an agreement to let the FSA lead for public reasons, because they don’t want to frighten Jordan or the West,” said an activist who works with opposition groups in Deraa.

Operations that were really carried out by Al Nusra are publicly presented by the FSA as their own,” he said.

A leading FSA commander involved in operations in Deraa said Al Nusra had strengthened FSA units and played a decisive role in key rebel victories in the south.

“The face of Al Nusra cannot be to the front. It must be behind the FSA, for the sake of Jordan and the international community,” he said….

“In many battles Al Nusra takes part, but we don’t tell the [foreign-staffed] operations room about it and sometimes we’ll even say that Al Nusra fighters are really from the FSA to enable them to move more easily across borders,” the commander added.

The relationship complicates the US line that any military supplies given to the insurgents must not be passed to JAN.

FSA commanders said weapons supplied to them by the operations room have not been shared with Jabhat al-Nusra fighters; however, JAN gets at least 20% of any weapons seized in joint raids on regime bases.