The Libyan army has this week scored a notable success in its fight against Daesh (the self-proclaimed IS) and its local Al-Qaeda offshoot, Ansar Al-Sharia. For the best part of 18 months, the army has been struggling to clear the terrorists out of the southwest of Benghazi, Libya's second city. In just three days, the military has made sensational progress driving the terrorists out of three long-contested areas and, most importantly, capturing the small port from which Daesh and its allies had been bringing in weapons and reinforcements and ferrying out their wounded. Though there are still three main areas yet to be retaken, Benghazi has been gripped with wild enthusiasm. Convoys of honking, flag-draped cars have been driving through the streets and many hundreds of families who had fled their homes have been flooding back, sometimes to find only ruins. Triumphant citizens have been posting "Game Over" messages on social media. Unless there is a remarkable turnaround, which is hard to see, the terrorists in Benghazi are doomed. The victory ought to be a cause for celebration throughout country and in the United Nations which has spent 18 months brokering a Government of National Accord. However, the response from the rebels who seized Tripoli has been one of outrage. This makes clear where the Muslim Brotherhood-dominated Libya Dawn movement really stands. It was Misrata, the major militia supporter of Libya Dawn that had been the other end of the terrorist sea supply route to the now captured port southwest of Benghazi. The reason for this is clear. The victor in Benghazi is Khalifa Haftar, the former Gaddafi general who rebelled against the dictator and who was appointed to head the army by the internationally recognized parliament, the House of Representatives, currently based in Tobruk. Haftar is still characterized as a Gaddafi bogeyman and his forces are made up of supporters of the old regime. It matters not that the real Gaddafists have been actively supporting Daesh in Sirte, the slain dictator's hometown. The main accusation is that Haftar is seeking to make himself Libya's military ruler. There is evidence for this. At one point last year Haftar was pressing for the establishment of a military council to run the country, replacing the government of Abdullah Thinni which was appointed by the HOR. In the wake of this week's stunning military success, a huge banner lauding Haftar has been unfurled on a building in Benghazi. The problem for NATO, as it gears up to attack Daesh positions in Sirte and the surrounding northern coast, is that Haftar's victory threatens to unravel the Government of National Accord, which is made up of both rebel and HOR supporters. The rebel ministers are implacably opposed to Haftar and the idea that he should lead the Libyan armed forces. Even if the parliament approves the new government, as it is required to do, there is now no guarantee that the GNA will be able to hold together, let alone move from Tunis to Tripoli where the UN-brokered deal requires it to be. The Misratans in particular loathe Haftar. They were once seen as wavering in favor of the Government of National Accord. NATO has been looking for allies in its war against the terrorists. It now faces the awkward truth that Haftar looks like the most obvious choice.