With Assad Challenged, a Push to Cut Syria’s Ties to Iran Grows More Unlikely

For months, his country was battered by escalating Israeli bombardment, while behind the scenes, the United States and Gulf countries courted him diplomatically. It was a secretive, two-pronged approach meant to pressure President Bashar al-Assad of Syria to abandon his most important regional alliance with Hezbollah and Iran.

The overtures to Mr. al-Assad were the product of what Israel and its allies saw as a rare but risky opportunity — with Iran’s regional network fracturing under Israeli attack, they hoped to force Iran’s most important partner out of the alliance, according to former U.S. officials, two European diplomats and four Israeli officials who spoke on the condition of anonymity because of the sensitivity of the subject.

Now, those regional ambitions may be derailed by a far smaller and long-discounted force: Resurgent rebels have launched a surprisingly successful attack in Syria, exploiting in part the strain Israel has put on the alliance that helped Mr. al-Assad maintain power through more than a decade of uprising and civil war. In a matter of days, the rebels seized most of the country’s large city of Aleppo, and challenged Mr. al-Assad’s grip on the country’s northwest.