President Bashar al-Assad is losing the important military advantage of fighting a fragmented rebel movement which, at one time, the US said consisted of 1,200 different groups.
Mr. Eliasson said that the fragmented rebel groups fighting the government had merged into five identifiable groups, but that only two of them were willing to consider even the preparatory steps to peace negotiations.
Idriss D?, Chad's president, told the visiting secretary general, Ban Ki-moon, that he would offer leaders of the fragmented rebel movement in neighboring Sudan the opportunity to meet in Chad beforehand to help them "smooth over the rough edges" prior to the peace negotiations.
The opposition in exile remains unable to unify fragmented rebel groups behind its political leadership, even those that nominally fall under the umbrella of the opposition's Free Syrian Army, let alone the growing cadres of extremist Islamist fighters who openly reject the opposition leadership.
Meanwhile, the presence of Islamist extremists in the fragmented rebel ranks, including Al Qaeda-linked fighters, has likely helped consolidate Assad's support among some core Syrian constituencies, including minorities and the urban elite.
The two men have been traveling extensively in the region, trying to bring the fragmented Sudanese rebel movement together so that the groups can take advantage of a perceived willingness in Khartoum to talk.
Syria's rebels are fragmented politically and militarily; some are religious extremists with professed ties to Al Qaeda.
9.16am BST Russia is 'key weapons supplier' Guardian journalist Martin Chulov has been looking at the flow of arms into Syria and concludes that while the Assad regime can rely on supply of weapons from Russia, material support for rebels is mostly fragmented and scarce.
The rebel movement is fragmented partly because pervasive army roadblocks and other nationwide controls have made it hard to form large brigades under a unified command.
And Israel may find that its most dangerous foe is not Hezbollah but jihadist Syrian rebel groups that are fragmented and difficult to deter.
