The Democratic Union Party is the strongest Kurdish faction in Syria. It claims a force of 10,000 fighters, which are organized under the Popular Protection Units, and has a robust civilian following that has built up political support through local councils in northern Syria. The Democratic Union Party is also highly controversial among the Syrian opposition. Since the summer of 2012, when Iraqi Kurdish leader Massoud Barzani tried to unite Syria's Kurdish factions, the Democratic Union Party nominally has been part of the Kurdish Supreme Council, a coalition of some 15 other Kurdish groups, including Barzani's Kurdish National Council. Despite inclusion in the coalition, the Democratic Union Party has clashed regularly with other Kurdish coalition members as well as with Sunni Arab rebels from the Free Syrian Army. In its efforts to sever Alawite supply lines into Aleppo, the Free Syrian Army has encroached on Kurdish territory. Subsequent Democratic Union Party attacks on the Free Syrian Army have led to allegations that the Democratic Union Party was aligned with Alawite government forces to distract the Free Syrian Army from its offensive against the regime. Turkey, meanwhile, has deep concerns that a fortified Democratic Union Party in Syria will further radicalize the Kurdistan Workers' Party in Turkey (the Democratic Union Party has close ties to the group), with which the Turkish government is already struggling to negotiate a peace deal. The last thing Ankara needs is more hawkish Syrian Kurdish members of the Kurdistan Workers' Party derailing these talks and heightening the Kurdish militant threat in Turkey. As the leading figure in the Iraqi Kurdish political scene, Barzani is trying to demonstrate that he can rein in the Democratic Union Party to advance Iraq's negotiations with Turkey on creating alternative export routes for energy from Iraq's predominantly Kurdish north.