Some analysts say bases here were the source of chemical weapons fire that killed hundreds in August, prompting the deal to eliminate Syria’s chemical arsenal; the government denies that. What is not in dispute is that artillery strikes from the general area target the suburbs daily, the sounds of launching shells echoing over the city.

“The Syrian Army for the sake of the safety of the people,” read a poster at a checkpoint where men in camouflage checked cars; one driver appeared to be handing over a bag of lettuce to a soldier. “Yes to reforms” was scrawled on a concrete barrier. Nearby, the twisted carcass of a burned tanker truck lay on the shoulder, unexplained and ignored by people waiting for rides.

Image Credit... The New York Times

On stretches between time-consuming checkpoints, truck drivers tried to make up for delays, rattling along at breakneck speeds. Signs that said “Traffic Police for Help” included a number to call. Despite everything, Syria’s traffic police are far more effective than those in neighboring Lebanon, pulling over drivers and writing speeding and parking tickets.

Leaving the Damascus outskirts, the road continued between two ridges, the one to the west topped with vertical, bulbous stone formations. At a gap in the cliffs, buildings could be seen perched atop a rocky outcropping: the ancient Christian town of Maaloula, which rebels entered in September, prompting allegations they were intent on killing or driving out Christians.

Approaching Homs, the mountains to the west receded, signaling the end of the natural barrier between Syria and Lebanon. Here, where the northern end of Lebanon’s Bekaa Valley opens to the Syrian plain, the border has always been notional. Backed by its ally the Lebanese Shiite group Hezbollah, the Syrian Army fought a pitched battle nearby for control of the rebel-held border town of Qusayr and routes used by other Lebanese fighters, Sunnis joining the rebels. The government retook Qusayr in June.

In the town of Nabak just south of Homs, clashes have destroyed restaurants and buildings and left cafes like the Fun Palace deserted, their Ferris wheels still. Rebel checkpoints can appear here without warning to question and sometimes kidnap travelers. But in the next town stand the gleaming, apparently untouched campuses of the University of Kalamoun and a hospital named for Mr. Assad’s brother Bassel.