The Wall Street Journal reports: Before Russia started its bombing campaign in Syria in September, Syria’s moderate opposition bet a military offensive in the south of the country could change the course of the war and force President Bashar al-Assad to the negotiating table.

That summer offensive collapsed, bolstering Mr. Assad’s regime and depleting the ranks of mainstream rebel forces already struggling to stay relevant in Syria’s future. Mr. Assad and his Iranian and Russian patrons used the defeat to again portray the war as a fight against terrorism.

The failure of the offensive, dubbed “Southern Storm,” together with Russia’s entry into the war, shows the steep odds facing Mr. Assad’s opponents, both on the battlefield and in the next round of diplomacy scheduled for Saturday in Vienna, where foreign ministers from Iran, Russia, Saudi Arabia, the U.S. and other nations are scheduled to discuss a potential political solution to the Syrian conflict.

The offensive was viewed by moderate rebel factions, their foreign supporters and many civilians in southern Syria as an opportunity to show a viable alternative to rule by Mr. Assad or extremist rebel groups such as Islamic State and the al Qaeda-linked Nusra Front that now hold such sway on the battlefield.

By establishing a swath of territory near the capital Damascus that was administered by moderates and served as a sanctuary for civilians, they hoped to pressure Mr. Assad into a political settlement, said commanders for the rebel Southern Front, a coalition of moderate and secular insurgent factions formed in early 2014.

The rebel campaign has attracted little attention in Washington, and a senior defense official said the U.S. hasn’t provided any substantial help. The official said the operation does represent a large, coordinated rebel effort against the Assad regime. “We’re watching very closely and we’re hopeful that we continue to see” such efforts, the official said.

Mr. Assad and his allies appear, for the moment at least, to have regained some battlefield momentum—the regime has mockingly named a Russian-backed ground offensive against rebels “Northern Storm.” [Continue reading…]