"Don't even think about going to sleep tonight."

My fixer, Mahmoud Elzour, shot me a wry smile from the corner of a rooftop patio in a safe house in al-Bab, a town about 27 miles north of Aleppo that was recently liberated by Syrian rebels. It was already two o'clock in the morning, and the predawn meal that was supposed to get us through the Ramadan day ahead was being served by our host, Abu Ali. With his large frame and close-cropped brown hair, he could easily have been mistaken for a defensive tackle for the Miami Dolphins. We were surrounded by a gracious fraternity of activists, relatives of Abu Ali, and rebel fighters, among them one military defector and about four civilians. Earlier that evening, we had made a touch-and-go border crossing from Kilis, Turkey, and then drove for an hour along the completely quiet roadways leading from the border to al-Bab. The only military presence we encountered was a single Free Syrian Army (FSA) checkpoint. So after all this, sleeping had never occurred to me. "We will go to Aleppo at four and leave at noon," Mahmoud said. Was it safe? "Of course. I would not take you there if it wasn't, habibi." Another smile.

Reedy and bespectacled, Mahmoud is a 52-year-old Syrian who spent the last two decades in Atlanta. A few months ago, he sold most of his successful construction-vehicle dealership to move to Antakya, Turkey, where many Syrian fighters have formed an ad hoc base. Once there, he started financing his own rebel battalion. The day before our jaunt into Syria, he had returned from a fierce battle in central Aleppo that culminated in the rebels' overrunning two police stations and defeating a group of shabiha, mercenary civilian thugs employed by the regime, from the pro-Assad Barri tribe. Some members of the tribe were later summarily executed, and a gruesome video of the incident appalled even pro-opposition Syrians. Mahmoud took no part in the executions, but he did participate in a raid on one of the police stations. Rebels blew up the ground floor with with a bomb that had been fashioned, Mahmoud said, out of an old water boiler. The officers inside had been offered amnesty and safe passage if they quit their posts, but after hearing the scream of fighter jets overhead and mistakenly believing that reinforcements were on the way, they angrily refused. So the rebels invaded, killing anyone who fired back.

WAR OF ATTRITION

After nearly 18 months, with over 20,000 dead and millions more directly affected, the Syrian revolution has become the foreign policy preoccupation of every Western and Arab government. Syrian President Bashar al-Assad's few remaining allies -- China, Iran, and Russia -- show no sign of acceding to the aspirations of the Syrian people. And so what started out as a movement for economic reform, and was met with great violence, has now morphed into an armed insurgency, consisting overwhelmingly of civilians aiming to end the regime through force.

The Obama administration still professes not to know who the Syrian rebels are, even as busloads of foreign correspondents do the work of the Central Intelligence Agency in profiling them. The White House fears that the rebels' ranks have been infiltrated by extremist or sectarian groups, most notoriously al Qaeda, and thus is wary of committing money and arms to their cause. Some analysts cite this restraint as proof of the administration's prudence rather than of an incoherence that risks damning Syria to Washington's self-fulfilling prophecies. Those opposed to U.S. intervention warned that it would inevitably breed jihadism, sectarianism, and regional instability -- all of which have already come to pass. Meanwhile, Qatar, Saudi Arabia, and Turkey have had no such qualms about backing the opposition, albeit selectively and to further their own ideological interests. The rebels, for their part, have not equivocated in their call for outside help, giving weekly protests such names as "No-Fly Zone Friday." It is the West's hearts and minds that need winning over.

On the ground, however, the geopolitics of the struggle takes a back seat to more exigent considerations. The real story continues to be the unraveling of four decades of dynastic totalitarian rule. As horrifying as the carnage has been, the resilience of some segments of Syrian society leaves no doubt that the regime is finished. In parts of the country, an alternative to Assad's rule is already being joyously experienced and seen as worth dying for.

Still, nobody can predict with certainty when and how the House of Assad will fall. For all the braggadocio I heard from the Syrian rebels ("We will take Aleppo in no more than ten days"), their congenial shrugs over specifics revealed them to be far more interested in fighting a long war of attrition than in planning any well-timed march on Damascus. They can withstand losing a city street here, or a whole neighborhood there, because even in tactical defeat they cost the regime money, ammunition, and men. The rebels learn from their setbacks, too. In February, it took a month of brutal artillery bombardment and some 7,000 soldiers for the regime to retake Baba Amr, just one district in the city of Homs. The FSA had about 400 men, most of whom retreated when they ran out of bullets. Mark the sequel in Aleppo.

THE FREE SYRIAN STREET SWEEPERS

The chaotic news reports out of Syria do not prepare you for the eerie calm in the rural north of the country. Travel 50 miles from the border, and you'll barely realize you've left Turkey: Farmers drive along the main road in their tractors, many greeting you with a wave or a honk.

Such was the scene in al-Bab, at least when I arrived there two weeks ago. Since the start of the Syrian uprising, about 92 people have been killed there, 45 of them in the last month alone, after government forces started shelling the area. But when I came to this city of around 200,000 people, it was solidly under rebel control, thanks to the sacking of the nearby military camp that had carried out the shelling. The opposition fighters had even captured a few tanks. Within days, the makings of a civil society could already be glimpsed, especially at night. It was then that locals and rebels poured out into the streets, trading their cell phones and Kalashnikov rifles for garbage bags, white gloves, and brooms. Here were the Free Syrian Street Sweepers. Boys as young as 12 were at work all around the city picking up the day's trash or, in some cases, clearing rubble left after the siege.

One young boy told me he was on cleanup duty because for his whole life (and decades before that, too) to do anything spontaneous or willful in Syria required government permission. Another joked that the garbage bag in his hand was where he wanted Assad to go. The main boulevard was colored by minibuses emblazoned with the pre-Baathist Syrian flag -- rebranded the "independence" flag -- and pro-FSA slogans. Flashing headlights and loud horns gave the street an ecstatic energy that seemed completely at odds with the grinding and bloody civil war raging elsewhere. At a surprisingly chic hookah café with leather sofas and a plasma television, locals watched international news channels into the early hours of the morning. The strawberry smoothies were first-rate.

Yet the makings of a civil society are not the same thing as an actual civil society. As a recent video circulating on the Internet appears to show, during the siege of al-Bab, rebels threw the corpses of regime personnel off the rooftop of a post-office building that government forces were using as a security headquarters. Al-Bab opposition activists have since claimed that the bodies belonged to snipers who had killed seven rebels. They have also condemned the act and said that the identities of those who threw the bodies off the roof are not yet known. Still, this video is yet another reminder that Syria is a brutalized society. Even as some rebels try to act responsibly by adopting a martial code of conduct or putting their captives on trial before meting out punishment, they must overcome fear, sectarianism, and a deep-rooted sense of tribal justice. Lucky is the revolution in which the ennobling desire for freedom vanquishes the rebarbative impulse for vengeance.

Al-Bab is home to roughly 400 rebels and headquarters to one of the armed opposition's many Abu Bakr brigades, named for the Prophet Muhammad's father-in-law. Local merchants support the fighters with "salaries," a charismatic 32-year-old activist named Barry told me in the hookah café, in the amount of 5,000 Syrian lira ($100) per month. No money had come from outside the city. I asked Barry if the Syrian National Council, the largest umbrella group of opposition figures, which has been partially recognized by the United States, was sending aid of any kind into al-Bab. "No, no," he laughed. "They want someone [to] go there and -- I don't know the word -- 'please give me some money.'" To beg? "Yes, to beg."

Al-Bab has not seen help from the United States, either. When I asked a local activist, Muhammad Rajaf, what he thought of U.S. President Barack Obama, he made a derisive flapping gesture with his hand. "Obama . . . we see, talk, talk, talk. Don't see work." He had a higher opinion of Turkish Prime Minister Recep Tayyip Erdogan. Barry agreed, saying that the only countries a post-Assad Syria would have positive relations with were Turkey, Libya, and Tunisia, because all had contributed materially to the revolution. I then asked about the foreign fighters, some of them radical Islamists, who had reportedly infiltrated the Syrian opposition. Barry did not deny their existence, but he thought that the much-hyped menace of al Qaeda was one of the regime's greatest propaganda achievements. "Where are the terrorists here? You're with us now," he said to me, "so you can be the first Jewish-Christian member of al Qaeda." That did not mean that outside support for the revolution was necessarily secular or pluralistic. Barry called Saudi Arabia an enemy for its exclusive funding of Syrian Salafists, most of whom are based in the northwestern province of Idlib. "They want us to work with the Saudi agenda. We will not. We are a free people now." And free people, Barry said, need a free election. "At that time, I will accept the Salafi, the Ikhwan [Muslim Brotherhood], the liberal, anybody who wins fairly."

Until that election, though, the task of governing rebel-controlled territory is a tricky one. Al-Bab residents are trying to establish an emergency civil council to administer the city while the rest of Syria awaits its own piecemeal liberation. The council, according to Barry, is to be composed of a "first circle" of 21 members to be elected by activists in the city who "have been with the revolution from the first day." The FSA will not be involved, and the same goes for any of the initially nonviolent civilian activists who have since taken up arms. Merchants and latecomers to the revolution -- "the old men," in Barry's coinage -- would have subordinate roles in a "second circle" of councilmen that would be responsible for media, relief, and medical treatment, in effect bringing all of the de facto governing bodies in al-Bab under one heading. It sounded like a nice plan, in theory.

TRIAGE IN AL-BAB

If the FSA does cede authority to al-Bab's civilian-only municipal government, it might be because the militia's priorities lie elsewhere at the moment. Each day, fighters in al-Bab make the 35-minute journey to join the "mother of all battles," as the regime has termed it, now being waged in Aleppo, Syria's most populous city. The regime's unrelenting aerial bombardment campaign, using helicopters and fighter jets, has yet to be matched by an equivalent ground assault. That will come, as Syrians are wont to say, "tomorrow." Last week, the most severe clashes were raging in the neighborhood of Salaheddine, in southwestern Aleppo. In a video that Barry showed me, the neighborhood was a blasted-out ruin with decaying corpses in the street. He had just returned from the area, where he was hit by sniper bullets that ricocheted off the ground and entered his lower back and upper thigh. He had spent a few hours in the al-Bab field hospital (located in the basement of a mosque), got himself stitched up, and was ready to head back into Aleppo.

The field hospital is another testament to the resilience of al-Bab. At around eleven o'clock at night, Ilhan Tanir, a Turkish-American journalist, and I were taken there on motorbike to meet the volunteer staff members. They were eating in the corner of the expansive, fluorescent-lit center for triage and surgery. The entrance was filled with boxes of medical supplies, all moved from the actual hospital, which had been destroyed by regime forces. The room housed a single patient recovering from an unspecified head injury, but I could see traces of earlier casualties, including a dried pool of blood on the floor next to one gurney.

An electrical engineer who asked to be identified as Abdullah Mowahed told us, in perfect English, that it was his responsibility to keep a digital record of every case that passed through the hospital. He opened a laptop and showed me an Excel spreadsheet with the names of the patients, their places of origins, the type of injuries they had sustained, and their status -- civilian, rebel, or regime -- all organized like an accountant's ledger. The staff also recorded videos to document the patients' treatment, and the media team uploaded them to YouTube. One video showed a girl no older than ten whose back was covered by the scattershot rubies of a shrapnel wound; another showed a man whose legs were mangled beyond recognition. These were the victims of the bombardment campaign. "That was a hard time," the male nurse who seemed to administrate everything told us.

I asked about regime fighters treated here. Another volunteer named Muhammad replied that they received the same care as everyone else. "We tell them, 'What you do when you leave is up to you. But if you return to the army, you'll likely be killed because they will assume you've joined the opposition.'" Most, he said, defected or ran away.

Mutiny has been one of Assad's biggest fears since June 2011, when a lieutenant colonel named Hussein Harmoush turned his guns on regime forces who were firing on unarmed civilians in the northwestern town of Jisr al-Shughour. The majority of soldiers in the Syrian army are Sunnis, and whenever they are deployed into population centers -- usually on orders to fight "terrorists," or even Israelis -- a large bloc of them inevitably defects. As with Stalin's Red Army in World War II, Syrian regulars who make contact with the opposition and do not join their ranks can be held under lethal suspicion. A colonel who defected to Turkey in March told the London-based newspaper Asharq Alawsat: "[I]f an officer is discovered watching a channel other than the official Syrian channel, he will be punished; even when he goes to visit his family, he is allowed only one day, or 'a night.'"

THE MOTHER OF ALL BATTLES

For all the free-flowing traffic, leaving al-Bab is not easy once you arrive. As our party was preparing for our 4:00 AM jaunt into Aleppo, we faced a setback: no gas. After more than a year of U.S. and EU sanctions, not to mention the regime's own version of collective punishment, petrol was selling for $13 per gallon -- that is, for those lucky enough to find any to buy. Rebels have routinely seized gas trucks traveling through Syria, so drivers are reluctant to risk going to work. Not one to give up, Barry had a plan: Rather than head to Aleppo ourselves, we'd join an FSA convoy.

At around 5:30 AM, Abu Ali drove Mahmoud, Barry, Ilhan, and me the short distance from his house to a rebel gathering point at the southern tip of the city. There, we were met by a small war fleet: one pickup truck, an SUV with a mounted machine gun, a sedan (that was our ride), and a white minivan. After some cries of "Allahu Akbar," the convoy got moving.

As with the journey to al-Bab, the main highway leading to Aleppo was void of any regime presence. There were no FSA checkpoints in sight, either. Civilian vehicles passing us from the other direction honked or waved at the rebels. As we pulled into the liberated parts of Aleppo City, however, the pastoral scenery faded into that of a devastated war zone. The quiet indicated either a long-awaited cessation of violence or a prelude to another attack. Hundreds of thousands of people had fled in the last few weeks -- to other cities or to neighboring countries -- and scores of rebels, civilians, and regime fighters had been killed. At this point, I noticed that the white minivan ahead of us had its side door open -- the rebels inside were ready for anything.

A burned-out and graffiti-covered bus, which Barry claimed had been used to transport shabiha, lay in ruins on the side of the road. Garbage had not been collected in days, and the stench wafting in through the car window was eye-watering. A few residents and street vendors were out, tending to their businesses with an air of resignation or shell-shocked obliviousness. Even in hell, you have to eat. A long line had formed outside one building next to a cemetery. Barry said the people were waiting for bread. "Now it's not crowded, by the way." The line would grow longer later in the day.

We stopped somewhere along the way so that our convoy could consult with other rebels. Barry and Mahmoud got out of the sedan to find out where we were headed. "Where we are going," he said on returning, "I am happy." Given what he had been up to less than 24 hours before, I replied that what made him happy made me very unhappy. He laughed and reassured me that this would be a scenic tour that required very little running. Our destination, as we discovered, was Bab al-Hadid ("the Iron Gate"), a 500-year-old structure that marks the entrance to Aleppo's ancient city. The rebels had secured this area just days before; the freshly erected FSA checkpoints were manned by two or three fighters. Wooden milk crates were the only barriers that had to be removed to allow us to proceed to our destination, a parking lot across from a block of mostly shuttered storefronts and abandoned apartments. The armed fighters there, we were told, hailed from several different battalions. A middle-aged commander doled out instructions to each soldier. Some would be sent to guard checkpoints, others would deploy along a 650-foot perimeter around our location, in territories still very much controlled by the regime. "If you walk five minutes that way," Mahmoud said, pointing down a wide street that ran parallel to the Iron Gate, "you will be in downtown Aleppo. You'll also be in snipers' alley." Two guardsmen sat watch in front of a doormat with an image of Assad woven into it. Barry stepped on the dictator's face.

If any fighting was taking place this early in the morning, it was far enough away from us that we could not hear the shots. We spotted a helicopter flying a mile above us, although it did not appear to be getting ready to fire.

Civilians and yellow taxicabs wove in and out of this FSA safe zone all the time, evincing a life-must-go-on attitude in defiance of both sides. Unlike other sympathetic hotspots in Syria, Aleppo was still the latecomer to the revolution -- a city of Barry's "old men." At our hotel back in Turkey, Mahmoud had run into a wealthy Aleppine businessman who denied that the regime was bombing the city. "What does he think, that the rebels have jets and helicopters?" Mahmoud recounted to me indignantly. Aleppo is Syria's economic and industrial heart, and many revolutionaries suspect that its inhabitants care more for their wallets than their political freedoms.

No doubt there were some residents of the city who were downright hostile to any FSA presence, but on the whole most seemed indifferent. The imam of a local mosque, which rebels had turned into a sleeping quarters, was quite friendly, however. He brightened when I told him I was an American, and perhaps because we looked like we had not slept in days -- Mahmoud certainly had not -- he invited us to rest in his mosque. Lying down on an embroidered carpet, I looked up at the chandeliers screwed into the arched ceiling and noticed that they held energy-saving bulbs. I fell asleep with the grimly amusing thought that small touches like these must have contributed to the Western delusion that Assad, a London-educated ophthalmologist with a runway-model wife, was a reformer. As we dozed, the distant thud of shelling could finally be heard.

When we awoke a few hours later, we set out in search of caffeine before making the trip back to al-Bab. In a dingy alleyway, a group of four rebels invited us to squat on the curb with them and drink chai. The leader of this platoon, Abu Muhammad, was a civilian who used to build military housing. He carried a pistol in his belt. Many Aleppines, he told me, still support Assad. Even in the liberated area around the Iron Gate, shabiha occasionally shoot at rebels from rooftops. I asked about the presence of foreign fighters in Aleppo, since news reports have suggested that radical Islamists from abroad had joined in the battle for the city. He said that the only foreign fighters he knew of were Iranian snipers operating near the citadel and Russians who were embedded with Assad's regular army. I took his statement with a grain of salt: Iran has admitted to a Revolutionary Guard Corps presence in Syria, but no credible evidence suggests that Russia has dispatched any forces, at least not yet. Still, in a country where paranoia and conspiracy theories masquerade as state-sponsored news, it is hard to fault any Syrian for rumormongering.

A small crowd had gathered around us by now. One rebel, perhaps thinking I had not fully grasped the enormity of his struggle, handed me a semi-exploded mortar.

NUMBERED DAYS

Within 48 hours of my leaving Syria and returning to London, the regime had once again taken to shelling Bab al-Hadid, as Western newspapers reported that the rebels controlled between 50 to 60 percent of Aleppo. Assad's anticipated ground offensive had not yet materialized, but now the regime's most advanced warcraft, MiG fighter jets, were indiscriminately targeting FSA strongholds and civilian homes alike. Richard Spencer, a correspondent for the British Daily Telegraph, stood in front of one house where members of the Kayali and Katab families were wiped out by two missiles. A ten-year-old girl's head, Spencer reported, "was attached to a torso that ended at her stomach." Meanwhile, the newly appointed Sunni Prime Minister Riad Hijab and his family had just defected to Jordan after a dangerous holdover in an FSA safe house in the southern city of Daraa. He had reportedly been coordinating the move with the opposition for almost as long as he held office.

All these defections and rebel victories underscore the assertion, a favorite in unassertive Washington, that Assad's days are numbered. But what number? And under what conditions will his tyranny come to an end? No one I met in Syria had the answer. Unless the West plans to hasten that eventuality directly, it should not claim to, either.