As Syria’s second peace conference looms, and we prepare ourselves for a lot of hot air drifting over from Geneva, I’ve been making a list of those players in the civil war who actually want peace and those who don’t fancy it one bit.

The anti-peace side is easy. There’s Bashar al-Assad, of course. Hillary saw to that during the first conference. Perhaps she’s right that he shouldn’t be part of any transitional government, but if he loses all power, Assad and his Alawite clan are toast. So what use is peace to him? The rebels of the Islamic Front alliance are the latest Washington craze; they’re the alliance of ‘moderate’ extremists some East Coast optimists think we should support, but even so they can’t be said to want peace: they hate America and remain set on war and sharia law.

Then there are the real bad boys, the rebels with a global cause: Al Nusra (affiliated to al-Qa’eda) and worse: the foreign fighters of ISIS, who are set on carving an Islamic state out of north-eastern Syria and western Iraq. A few weeks ago, they took Fallujah, so they’re really making progress. For ISIS, peace would be actually satanic — an affront to jihad. Here’s their latest communiqué, which I think gets to the heart of their philosophy: ‘Our army is full of hungry lions who drink blood and eat bones, finding nothing tastier than the blood of Sahwa [the other rebels],’ they said. Take that, Geneva.

So does anyone on the ground have any interest at all in calming things down? There are the official rebels, the Free Syrian Army. They’re on the pro-peace list although the best of them are in despair and the worst increasingly into beheadings. And I’ve also added one Catholic priest by the name of Father Paolo Dall’Oglio.

Perhaps it’s odd to single out one man, but you take good news where you find it in Syria, and Fr Paolo might be unique. If anyone has a cat’s chance in hell of rallying the right rebels in a post-Assad Syria, it could well be him.

Fr Paolo’s an Italian Jesuit of sixty-odd who fell in love with Syria as a teenager and went back there with a vocation, he said, to promote peace between Muslims and Christians. He’s been there three decades now, debating the nature of God with Sunnis, Christians, Shia and Alawites, and teaching that Christians shouldn’t just tolerate Muslims but love them. He’s spoken of with respect throughout the country. ‘Abouna Paolo’, they call him, and when I visited Syria eight years ago, all manner of otherwise pretty taciturn types smiled at the mention of his name.

When the war broke out, many Christians fled. Sensible of them, really, because more often than not they were seen to as allies of Assad and once he lost his absolute grip, they were vulnerable. Fr Paolo stayed put. He’s a wily as well as a holy man, and he used his understanding of the various sects to mediate between warring groups. He marched with the Free Syrian Army, negotiated for the release of prisoners, lobbied on behalf of the Kurds. Wherever real trouble broke out, Paolo was drawn towards it — sure that he could talk down even rabid jihadis. You might remember a to-do about Christians being hounded out of a town called Qusair. Well, there was Fr Paolo in the thick of it, negotiating with both sides and praying and fasting for peace.

I met Fr Paolo only once, in the desert monastery he restored just north of Damascus. He’s a formidable chap, charismatic and vast with a great boulder of a head, so at first I laid low and listened. As darkness fell over the desert, young Muslims and Christians gathered round him and debated the nature of Christ.

The next day, feeling braver, I asked Fr Paolo whether he thought Islam or Christianity better. He grinned and said (my diary says): ‘I don’t compare. I have great respect for Islam, but all I know is my experience. I learnt about Jesus Christ, I walked with him and I discovered his divinity.’ I was surprised at the time, expecting this famous Islamophile to say that any path will do, but Paolo’s faith is what Syrians respect. In a region united by belief, only relativism is really suspect.

It was in the spring of last year that things really began to go badly awry in the north of Syria. A loose alliance of rebels took the city of Raqqa on the northern bank of the Euphrates, but as the Syrian Sunnis were celebrating, the foreign Islamists began to paint the town black. Soon, churches were ransacked and the ISIS flag raised above them. Before long, impromptu sharia courts appeared and those blood-hungry ‘lions’ of ISIS began their usual routine: executions, beheadings and torture.

Who dares brave Raqqa? Fr Paolo, of course. In late summer he smuggled himself into town with the help of Kurdish fighters and went to try to talk peace to ISIS. This isn’t quite — quite — as crazy as it sounds: there’s a stream of politics running through any sectarian bloodbath and Paolo went in part to talk to the local bigwig who has the ear of the rich Saudis who (bless their hearts) sponsor ISIS in Syria and Iraq.

It didn’t pay off for Paolo this time. The last footage of him is on Youtube, at a rally in Raqqa — his big head high above the crowd, rallying the crowd, calling for peace. A few days after that he disappeared, bundled into an ISIS prison, and since then: silence. Some have it that he’s being held near the Assad dam, others assume he’s dead — but I think not. He’s too important a bargaining chip and ISIS knows his worth. Another great Jesuit, Pope Francis, said a prayer for Paolo’s safety on the feast of St Ignatius Loyola last year — and in many things they are as one: Francis shocked the world by washing a Muslim’s feet last Easter and Paolo shares the Pope’s passion for the poor.

Even if the Pope can save Paolo, he has no chance of keeping him out of Syria. The troublesome priest will stay put — and perhaps this face-to-face with ISIS is somehow the culmination of his vocation. At any rate, when next week all the talking heads are in despair about ISIS, keep in your mind that, in a prison cell somewhere in the desert, there’s every chance Fr Paolo will be conducting his own peace process.