There is one main road stretching north-south along the Bekaa valley between Lebanon and Syria. It runs in a beeline from the prosperous little city of Zhaleh, on through a series of villages each with its own religious bent — some Sunni, some Christian — to the border town of al-Qaa, then on into Homs and the bloody mess of the Syrian war.

We’re just short of the border when what has been an uninspiring landscape, a wafting sea of plastic bags caught on desert shrubs, springs suddenly to life. Out of nowhere: orchards, vineyards, fig trees; aubergines fat and fallen on the grass. The air is sweet with the smell of apples.

Dr Bassam El-Hachem, professor of sociology at the Lebanese university in Beirut and a big hitter in Lebanon’s FPM party, is our tour guide today on this jaunt to visit Christian refugees. He leans over his shoulder, to address the minibus (one priest, two hacks and the Doc’s flamboyant blonde wife). ‘The source of the Orontes river!’ He points, we nod. The Orontes, we learn, runs from here into Syria spreading rich, fertile soil through the Wadi al-Nasara — the valley of the Christians — up ahead. It traces the course of the fighting, past Hama and Idlib province into Turkey. On our return trip, I look at the Orontes in a different light, because though the conflict in Syria is fuelled by religion and repression, I suspect this river plays a part too.

As we pull into al-Qaa, the minibus team grows quieter. We drive past the checkpoint and peer into no man’s land. This is the portal through which the refugees escape from Syria into Lebanon: not just Christians, also Shia, Sunni and Alawite (Syrian President Bashir al-Assad’s family are Alawites). It’s still reasonably safe on this side of the border. Syria’s war hasn’t spilled over into Lebanon yet — but it’s a very precarious peace. Hezbollah has formed a little pro-Assad gang with the Christians and have a grip of this area here. In Aarsal just a few miles away, the Sunni population supports the rebels of the Free Syrian Army. Under the cover of night, both sides steal across the border to fight.

But in the mayor of al-Qaa’s house, all is calm. The windows are bulletproof, the shelves heavy with bottles of expensive drink, and we sit in the usual way on seats around the walls, like patients in an old-fashioned waiting-room. After tea, the Christian refugees who’ve been corralled in here tell their stories.

First up is Boutros (not his real name), a 26-year-old from the nearby Syrian town of Qusayr where once Christians and Sunnis lived side by side. So how did the fighting start? ‘At first the Sunni rebels offered us a choice: join us or leave. When we refused, they turned on us. Our neighbours!’ says Boutros in outrage. ‘Then the Sunnis began to threaten us. They would shout: “Christians to Beirut, Alawites to the grave”.’ This chant is so often repeated and reported, it’s become almost the official jingle of the civil war.

According to Boutros, a Christian called Matthew Kasouha was the first one killed in the spring of last year. Kasouha came from an important clan, and so other Christians arrived at his family’s house the next day to offer condolences — only to find themselves under fire too. ‘The mourners were shelled by the rebels, and this was when people began to understand that they must leave,’ says Boutros. In March this year there was showdown: ‘The Sunni Islamists launched another attack on the Kasouha family, they were all killed.’ And what is Qusayr like now? Boutros looks down at the floor. ‘It’s bad. There are snipers in the streets, shooting at everyone who moves. Even in your house you can be shelled.’

Who are these snipers? Are they locals? This question seems crucial. Everyone in the region is either for or against Bashir al-Assad’s regime, it’s a bipolar world: Christians and Shia mostly for, Sunnis mostly against. Dr Bassam and his wife are firmly in the pro-Assad camp, and they insist that the rebels are not locals with a legitimate grievance, but mostly Islamists from Pakistan or Saudi Arabia. ‘Mercenaries,’ insists the Doc’s wife.

But Boutros says: ‘Yes, they are locals,’ then he curls his lip and says a word in Arabic that it takes the assembled company a while to translate: ‘Low-lifes?’ suggests Dr Bassam. ‘Riff-raff?’ suggests his wife. Boutros goes on: ‘This is what they are like. One of the killers, the commander of the “Bara” brigade, was found with a syringe full of diesel. He injected it into a man, a Christian, saying, “Die slowly, you Christian dog”.’

Did you see this? I ask. How can you be sure? Boutros looks indignant: ‘He put it on YouTube.’ This has the ring of horrible truth. The web has become the site of a propaganda war where both Assad’s army and the rebels post horrific videos of atrocities they attribute to the other side. It’s better not to look.

Boulos, next up — also not his real name — is 24, younger and more haunted-looking than his friend, with dark circles around his eyes. He came to al-Qaa five months ago with his wife and children from the Christian village of Rableh, just across the border. Rableh has been under siege, he says. Ten per cent of the population has fled, some 100 families here to al-Qaa. Two weeks ago, says Boulos, the Sunni rebels captured and kidnapped 250 people from the fields surrounding Rableh, and though the Syrian army has arrived to protect them, rebel snipers still surround the area. ‘Two days ago another two people were killed by a rocket. I don’t know if I will ever go back. There’s no work,’ he says.

Everyone in the house is nodding now: the professor, the priest, the mayor. This is grist to the pro-regime mill. Hillary Clinton may cheer on what she insists on calling ‘brave Sunni revolutionaries’ fighting Assad’s evil army, but the consensus here is that if America arms the rebels, it will be giving guns to terrorists. ‘Throat-cutters,’ adds the professor’s wife.

And is this then the truth? A traduced government fighting murderous madmen? Yes, but only in part. There are militant extremists among the rebels, fighting under the black flag of al-Qa’eda. But what’s also true is that each side of this bloody squabble is so cross about the other side’s lies that it feels quite free to counter with some of its own. For instance, though the suffering they speak of today is real, the stories are -incomplete.

Take the sad tale of the Kasouha family, Boutros’s massacred friends. They are said to have links to the Assad regime, perhaps done their dirty work as part of the shabiha — the government’s civilian thugs. This may well be why they were targeted by the rebels, but no one here mentions it. In fact, they specifically deny it. ‘Matthew Kasouha was just a tiler,’ says Boutros, staring fixedly ahead. Did the regime, the army, commit any atrocities in Qusayr? I ask. He looks at the mayor and Dr Bassem. ‘No, not one.’

And as each side becomes more entrenched, the possibility of reconciliation becomes ever more remote, and paranoia begins to spread. ‘You’ve got to ask, who benefits most from this war?’ says Dr B’s wife to me in a stage whisper, across the table one night in Beirut. OK, who does benefit? ‘Israel,’ says Dr Bassam instantly, then relays a complicated theory about the benefit to Israel of weakening Syria and Lebanon through partition.

Does this sound weird to western ears? In the Middle East, it’s not an uncommon view. In Zhaleh, the Archbishop of the Bekaa Valley, the Most Revd John Darwish, gives us an audience to stress how important it is that we Europeans don’t follow America’s lead and consider arming the rebels. ‘We must have reconciliation, not war. And only Europe can achieve peace,’ he says. ‘If they don’t, the war will spread first to Lebanon and then even to Europe. The jihadis won’t stop. How much will England be affected in ten or 15 years?’ The question hangs in the air, almost like a threat. ‘This war is not between Syrians, it is between the powers of the world,’ says the archbishop darkly. And who are these powers? Who is the malign power behind it all? The archbishop momentarily loses his considerable poise. ‘America?’ he says weakly. The Doc’s wife says later: ‘He means Israel.’

Back on the border, in al-Qaa, the leader of the municipality has a more prosaic view, and this is where the Orontes plays its part. In Boulos’s village, as in many others in Syria, the Christians own the high-value land: the orchards and vineyards watered by the river. ‘Why would the Sunni rebels want the Christians to leave? Because they own the good land here, they are well off. The idea is that the rebels would take the land,’ he says. It’s the back story of revolutions worldwide.

Whether the cause is local or global, one sad fact is that the Christians are leaving Syria, and once they’ve left, most won’t come back. This is the least examined tragedy of the conflict — the exodus of Christians from their holy land.

In Beirut a few days ago, Dr Bassam led our little crew to the St Antoine dispensary in Beirut, run by the Good Shepherd Sisters of Lebanon. Sister Georgette, on duty that day, told us she was seeing more and more Christian refugees all the time, not just from Syria but from Iraq too. ‘They come! They come! They come!’ She flung her hands in the air, laughing. I spoke to the mothers at the clinic as they clutched their sloe-eyed babies. They wanted visas, they said, to Australia, to Sweden or South America. Quite specifically not to America.

It’s easy to see why they want another home, said Sister Georgette. Both the Shia and the Sunnis here have back-up, a big brother in the region: Iran for the Shia, while the Sunnis have Saudi Arabia or Qatar. The Christians are on their own, growing more anxious all the time. Sister Georgette is a little ambivalent about both the Syrians, who occupied Lebanon for years, and the Sunnis, who the Sisters in Damascus say are causing havoc, but even so she helps all-comers with grace and kindness. ‘Of course we help! They need us. They all need us.’ Oh for more Christians like Sister Georgette.

On the way back, the minibus paused for a moment on the flanks of Mount Lebanon and we looked down into Beirut. The pine trees were black against the evening sky, the sun was a blood-red smudge. We left Dr Bassam and his wife at the hotel and wished them luck: here’s hoping Lebanon stays out of the war, we said. The next day, just as we reached the airport, a bomb exploded in Beirut’s Christian quarter, killing one of the leading opponents of the Syrian regime. Since then, the fragile bubble of unity seems to have burst and the accusations have begun: it’s the Syrians, say the Sunnis; vicious lies, says Hezbollah. But who knows? Everyone’s telling a different story.