On Saturday, in Brega, I met Osama BenSadik, a forty-seven-year-old Libyan-American who had returned to his homeland from Martinsville, Virginia, to help the revolution. He was offering his services in the hospital. (He is a volunteer firefighter in Henry County.) He told me, full of passion and pride and fear, that his twenty-one-year-old son, Muhanad, a second year medical student and a Boy Scout, who had been in school here in Libya, had gone to fight at the front line. “Tell America to come and help, because if we don’t, if we let the Libyan revolution fail, then we—you and I and all of us—would see things we could never imagine,” he said. It wasn’t a full-formed thought, but I understand BenSadik to be referring to the roiling and sometimes contradictory emotions among the young fighters at the front, who were watching their friends be slaughtered, and trying to come to terms with what it all meant. BenSadik told me that he feared for his son’s safety because he was brave, and had told him that he felt the revolution was a cause worth dying for.

The next day, I was at what remained of Libya’s rebel front line on the western edge of Ajdabiya, the eastern town that is a gateway to Benghazi. A large green gateway surrounded the trash of men at war and slag heaps of construction offal. A smattering of anti-aircraft batteries and a few hundred tense and dispirited men standing around with weapons, staring at the horizon, were all that seemed to be left of the euphoric crowd of several thousand civilian men and boys-turned-revolutionaries who had sung and danced and chanted at that same gateway as they readied themselves to attack and vanquish the hated Qaddafi regime just twelve days ago. After arming themselves with weaponry captured from police and army facilities, they charged westward, hoping to liberate the rest of the country. Members of the old Army supposedly joined them, but evidence of their support is scant. Without the help or advice of professionally trained soldiers and officers, the last ten days or so have seen the rebels—the youthful ‘shabbab,’ as everyone calls them—bloodied at the oil towns of Ras Lanuf and Brega, west of here, and retreating in ever increasing panic and disarray.

The rebels have lost ground because they have not learned how to hold it. At the front lines at Ras Lanuf and Brega, they didn’t dig trenches, and so when jets came to bomb them they panicked and ran. Last Friday, I was with them as they abandoned what had been their new fallback front line, in front of the refinery east of Ras Lanuf (having lost the town itself the day before) under withering barrages of rocket fire. That night, I slept in Brega; when I ventured back, the next day, to see if there was anything left of the front line, I found just fifteen or twenty battlewagons at a checkpoint in the desert fifty miles east, near El Aquela. A few more technical vehicles with guns showed up from Brega to reinforce the line; a few were beyond, “probing “ the desert, according to an officer I talked to—one of the very few soldiers I had spotted anywhere near the front lines in recent days.

Suddenly, the sky filled with the approaching roar of a diving jet fighter, which swooped in and, as we scrambled next to a car, dropped a bomb about a hundred feet from where we were. Once again, as we had seen so many times in the previous days, everyone fled—because there was no cover, and nowhere to hide. At Brega, there was a kind of reassembly of men, but they were few, and there were, again, no fortifications, no trenches, and precious few guns. The next morning, Brega, too, was abandoned amid similar scenes, as Qaddafi’s forces, coming onwards, heralded their intention to advance with long-range rocket fire and more aerial bombardment.

For days now, all the fighters have come up to Westerners like myself and asked, with varying degrees of passion, “Where is Obama, where is America?” They wanted to know why the West has, as they see it, dragged its feet about a no-fly zone. It had become clear that without some kind of international deterrent force the rebellion would fail. From here, the arguments being used against a no-fly zone, which seems a low-risk investment in the anti-Qaddafi revolution, have been impossible to fathom. It worked in Serbia, after all, and the West had managed to impose and then enforce a no-fly zone with alacrity in Iraq after the first Gulf War, and then kept it in place for twelve long years. Why is it suddenly so difficult to impose one here in Libya?

In truth, even if a no-fly zone is imposed now, it might not be enough to stop Qaddafi’s advance. Its real value, as far as I have been able to ascertain, would be the symbolic importance, the morale boost it would give the fighters, to allow them to feel that they are not entirely alone in the world. It might even buy them enough time to rally more volunteers to stand and fight, rather than retreat, in the face of Qaddafi’s advancing ground forces—or at least to dig some trenches. If Libya’s revolutionaries are truly abandoned, however, anything is possible. An ideological incoherence seethes in these young people—trying to be brave, terrified and nonetheless going forward, and being blown to pieces—which could be exploited if their revolutionary euphoria turns to bitter resentment.

At Ajdabiya hospital yesterday, I ran into Osama BenSadik. He crumpled in my arms as I walked up to him, and his whole body heaved as he wept. Muhanad had been killed, fighting, not far from Brega, Saturday morning. BenSadik sobbed with a father’s inconsolable grief. He was at the hospital, waiting for the body, which he hoped would be retrieved—but he didn’t know, because it was Qaddafi territory now. If Muhanad’s body came, he told me, he would take it to his brother’s house in Benghazi and he would mourn for three days as in the Libyan tradition. Then he would return to the front. “I am not going to let Muhanad’s death be in vain,” he said. “I’m not going back to America until this is over. I don’t care about anything anymore.”

Slide show: Our coverage of the protests in Libya.

Photograph: AP/Nasser Nasser