The New York Times reports: It was a victory that President Bashar al-Assad’s opponents had dreamed of: Insurgents seized a key army base in northern Syria after more than a year of trying. But the mood in this Turkish border town, flooded with Syrians who have fled both government bombings and extremist insurgents, was more bitter than celebratory.

The assault this month was led by the Nusra Front, Al Qaeda’s arm in Syria, which claimed the spoils. By contrast, many of the first Syrians to rise up against Mr. Assad in 2011 — civilian demonstrators and army defectors alike — followed the battle from the sidelines here, unable to enter Syria under threat of death from the extremists of Nusra and its rival group, the Islamic State.

As Syria’s war heads toward its fourth year, the complex battleground is increasingly divided between the government and the extremists, leaving many Syrians feeling that the revolution on which they gambled their lives and livelihoods has failed.

Different insurgent groups battle one another, even as they fight against Mr. Assad’s forces and his allies, foreign Shiite militias. A chaotic stalemate reigns in a war that has killed more than 200,000 people and wounded one million.

In northern and eastern Syria, where Mr. Assad’s opponents won early victories and once dreamed of building self-government, the nationalist rebel groups calling themselves the Free Syrian Army are forced to operate under the extremists’ umbrellas, to go underground or to flee, according to Syrian insurgents, activists and two top commanders of the American-financed F.S.A. groups. [Continue reading…]