Inside the Final Days of the Assad Regime in Syria

As rebels advanced toward the Syrian capital of Damascus on Dec. 7, the staff in the hilltop Presidential Palace prepared for a speech they hoped would lead to a peaceful end to the 13-year civil war.

Aides to President Bashar al-Assad were brainstorming messaging ideas. A film crew had set up cameras and lights nearby. Syria’s state-run television station was ready to broadcast the finished product: an address by Mr. al-Assad announcing a plan to share power with members of the political opposition, according to three people who were involved in the preparation.

Working from the palace, Mr. al-Assad, who had wielded fear and force to maintain his authoritarian rule over Syria for more than two decades, had betrayed no sense of alarm to his staff, according to a palace insider whose office was near the president’s.

The capital’s defenses had been bolstered, Mr. al-Assad’s aides were told, including by the powerful 4th Armored Division of the Syrian Army, led by the president’s brother Maher al-Assad, the insider said.

They had all been deceived.

After dusk, the president slipped out of the capital, flying covertly to a Russian military base in northern Syria and then on a Russian jet to Moscow, according to six Middle Eastern government and security officials.

Maher al-Assad fled separately that evening with other senior military officers across the desert to Iraq, according to two Iraqi officials. His current location remains unknown.