The efforts to capture Aleppo, which was launched last year but were delayed due to the war in Gaza, were launched last week after the cease-fire between Israel and Lebanon, the leader of Syria's main opposition group said Monday.
The insurgents were able to seize the city and parts of neighboring Idlib province so quickly in part because Hezbollah and other Iran-backed fighters were distracted by their conflict with Israel, Hadi al-Bahra said in an interview on Monday.
The Turkish military, which is allied with some of the opposition forces and has bases across its southern border in Syria, had heard of the armed groups' plans but made clear it would play no direct role, he added.
The assault in northwestern Syria was launched last Wednesday, the day that Israel and the Lebanese group Hezbollah began a truce ending more than a year of fighting.
"A year ago they started really training and mobilizing and taking it more seriously," said al-Bahra, president of the National Coalition of Syrian Revolution and Opposition Forces, the internationally-recognized Syrian opposition.
"But the war on Gaza ... then the war in Lebanon delayed it. They felt it wouldn't look good having the war in Lebanon at the same time they were fighting in Syria," he said in his Istanbul office, in the first public comments on the rebel preparations by an opposition figure.
"So the moment there was a cease-fire in Lebanon, they found that opportunity ... to start."
The anti-regime operation is the boldest advance and biggest challenge to Syrian President Bashar Assad in years of a civil war where the front lines have largely been frozen since 2020.
Syrian and allied Russian forces have launched counterattacks, which Bahra said are "destabilizing" Aleppo and Idlib and pose the biggest risk to civilians, given the earlier opposition advances had sought carefully to avoid such casualties.
The opposition retaking of Aleppo also paves the way for hundreds of thousands of Syrians displaced elsewhere in the country and in Türkiye to return home, Bahra said.
"Due to the Lebanese war and decrease in Hezbollah forces, (Assad's) regime has less support," he said, adding that Iranian militias also have fewer resources while Russia is giving less air cover due to its "Ukraine problem."
Iran-backed Hezbollah did not immediately comment on whether its war with Israel opened the door to Syrian opposition advances in Aleppo, where it also has personnel.
Tehran has pledged to aid the Syrian government and on Monday hundreds of fighters from Iran-backed Iraqi militias crossed into Syria to help fight the opposition, Syrian and Iraqi sources said.
A Turkish defense ministry official said last week that Türkiye was closely monitoring the mobilization and taking precautions for its troops.
Bahra's coalition, which does not include HTS, represents anti-Assad groups including the Türkiye-backed Syrian National Army or Free Syrian Army, which took territory north of Idlib over the last week.
It holds regular diplomatic talks with the United Nations and several states.
