It was a dispute in a university cafeteria that erupted into the worst sectarian violence in Lebanon in 15 years. How it started and who is to blame depends on which side tells the story.
But even as young Shiite and Sunni men on both sides armed themselves for a bloody face-off last Thursday, their parents begged them to stop – horrific images of Lebanon's 1975-90 civil war rekindling in their minds.
The political standoff between the government and opposition, simmering for two months, has taken an increasingly violent and sectarian turn in the past week, exposing long-dormant divisions between Lebanon's Sunnis and Shiites, and rival Christian factions.
At stake in the spiraling conflict is who will define the identity of Lebanon, a colonial-era construct that includes 18 confessions, and in recent decades has served as the proxy battlefield for broader regional struggles by Israel, Syria, Palestinians, and today, the US and Iran.
"My mother was crying ... and telephoned me to come back," says business student Alaa, a Sunni who dismissed his mother's pleas on Thursday, as black smoke from burning cars belched above the largely Sunni Tareq al-Jdideh neighborhood.
"They know about the civil war and they fear it again," says Alaa, speaking of his parents. "[But] if we do not do this and defend our homes, [Shiites] could come and invade and stay."
That battle pitted Sunni supporters of the Western-backed government of Prime Minister Fouad Siniora, who dominate the area around the Beirut Arab University, against Shiite Hizbullah and Amal loyalists who want to topple the government and who called in armed and helmeted reinforcements to back up their students.
The specter of renewed conflict could mar the ambitions of both Lebanese camps and jeopardize a transformation that has rebuilt Beirut from the ashes of civil war. Lebanon is still reeling from the 34-day war this summer, between Hizbullah and Israel, that devastated the nation's infrastructure. Donors in the Western camp met in Paris Thursday to pledge $7.6 billion to help.
"Only God can stop a civil war now," says a Christian father and former officer in the Lebanese Forces militia of Samir Geagea, a Christian leader once indicted for wartime killings. Two of his sons are in the Army, which has so far not been overwhelmed by the spasms of violence.
"We're between catastrophe and peace in Lebanon," he says. "The smallest accident could set it off, because blood is moving and is inflamed."
"For 15 years the TV and news showed there was peace," says another Christian, a militant who maintains a personal arsenal of two assault rifles, a pistol, and stocks of ammunition, hidden in cupboards and amid piles of clothes.
"But inside ourselves, we prepare for the next big fight. All groups have [prepared]," says the man, who asked not to be identified. "I don't believe we can all live together. There is too much religious racism, and hiding [of true feelings.]"
Those mutual suspicions have been edging closer to the surface, driven by uncompromising politicians willing to take their differences to the street. Violence first broke out last Tuesday when the Hizbullah-led opposition shut down Beirut and other cities with flaming barricades and gangs of club-wielding men during a one-day nationwide strike.
The further eruption Thursday was more shocking to many Lebanese, because the spark was apparently so small. Afterward, leading politicians of all stripes called for calm and a withdrawal from the streets.
Though it was quiet over the weekend, many Lebanese spoke of mistrusting politicians and concern that tension is rising beyond their ability to control the street.
"I didn't get scared in the past war, but now I am worried," says Adel, a Sunni who lives with his family behind Beirut Arab University. "I felt like I was completely in a trance [during the fight]. We are concerned it could get worse, but we hope it will end here. No one is looking for war.
"I told my sons: 'Stay where you are [at home]. Don't look for trouble,' " adds Adel, who would only give his first name.
But on Thursday trouble found plenty of young men – including at least one of Adel's sons – who admitted knowing little about Lebanon's past civil war or how such strife as they are engaged in helped precipitate it.
Rabiah, a Sunni student, said his parents "were terrified" by the vicious street scenes. A chunk of thrown rubble cut the right side of Rabiah's face and eye: "They tried to stop me going out, but I ignored them. I ran away from the house."
Rabiah ran directly into a conflict that had been ratcheted up by politicians and their taunting rhetoric.
Hizbullah chief Sheikh Hassan Nasrallah said he had limited the strike to one day in the interest of peace, but declared that his Shiite party and its allies had the "strength to bring down the unconstitutional government tomorrow or the day after."
Michel Aoun, a former general whose Christian faction is allied to the Syrian- and Iran-backed Hizbullah, said after the strike that "surprises" were forthcoming: "You can't imagine what we have in store."
Then after the Thursday riots, which only came to an end when the Lebanese Army intervened, pro-government forces countered with their own warnings. Saad Hariri, the parliament majority leader and son of former Prime Minister Rafik Hariri, who was assassinated two years ago, said: "Everyone has reached the red line, and here we have to back up and return to dialogue."
In a speech Friday, Mr. Geagea, whose Christian faction is pro-government, told Nasrallah that Hizbullah could not "alter the balance of power" in Lebanon: "If you go beyond democratic means, that will lead you to civil war, in which you will also not achieve your declared objective."
At street level, some of the worst clashes last week were between Christian groups, in Beirut and the northern city of Tripoli. Maronite Patriarch Boutros Sfeir complained that "such a reality makes our heart cry," as he noted that no sect was without blame.
"We used to think that some Lebanese were better than others," the Christian religious leader said, "but we discovered that all of them were involved in clashes and there isn't any difference between one sect and another."
Still, Christians are as concerned as any at the surge in violence.
"When we sit with [Muslims], we are brothers," says the armed Christian militant, speaking of his fears at his home. "But when Christians sit alone, we talk badly of them. And when Muslims sit alone, they talk badly of us. They don't like us, and talk of war."
"We want to live in peace, but in our way – freedom," says this militant, who says he narrowly missed being shot with a pistol on Tuesday when he went to open a road closed by Aoun supporters, fellow Christians. "We don't want someone to shoot up a shop if it sells arak [liquor], or throw acid in the face of a girl if she does not wear a veil.
"I hope it continues, this Sunni-Shiite fighting, and they kill off each other," says the militant. "They will kill our children after."
Such strong views are gathering voice in Lebanon, as activists openly chant sectarian taunts for the first time in years. Many of those on the front lines were mere toddlers at the end of the last civil war.
"We are really scared," says Deem, a Sunni woman studying for a masters degree in finance at the university. "The situation has not been safe, and no one knows about the future."
"It is a nightmare. But what I saw [in Thursday's clashes] was the beginning," says Deem. "It is a civil war already, and somebody should do something, to defuse it fast. The Lebanese need to do something."
Thursday after the clashes was "fine, everyone went home," she says. "But what about tomorrow? Or the day after tomorrow?"