So there I was, in our Shia mosque on Friday 10 days back, when a fellow worshipper, a man, bounded up full of smiles. We had met briefly once before. As I was rushing to the prayer hall he made me promise I would talk to him afterwards. And so I did. And wish I hadn't. Instead of feeling spiritually renewed I experienced ungodly fury and left the beautiful space filled with despondency.

We had an argument about Syria and my vocal opposition to Assad's regime. I didn't understand anything, said he, and was being deceived by the lying Western media. As part of that deluded group I pointed out The Independent's honest and intrepid journalists who had reported the ruthless repression, the BBC's Sue Lloyd-Roberts's high-risk missives from inside the bombardment of Homs... I may as well have sung "La-La-La" to the excited chap who wasn't listening, wasn't going to listen, didn't care to.

He was a businessman in Syria with factories employing many people, Shias in particular, he stressed as if that would sway me. The rebellion, he claimed, was a plot by outsiders (for a change, Israel wasn't one of the usual suspects) and backed by Sunnis because they want to crush minority Muslim sects, including the Allawi Assad family.

The man wasn't stupid, wasn't a Devil worshipper. He was just short-sighted as he looked across a vista steadily reddening with blood. All he wanted was tough control, good for business, just as apartheid was in its heyday. His interests were not that different from those of the powerful nations – China, Russia and, not that long ago, Britain, France and the US – for whom tightly run undemocratic Arab nations have always been damned good for business.

Such pro-Assad émigrés are terrified of a takeover by the Muslim Brotherhood or Wahhabi Islam – fears I share, as British Islam has now been overpowered by these forces. But the terror of regime change has expelled mercy and human fellowship, emotions instinctively aroused when we see a child's tortured torso, a mother's loss, an old man's bewilderment as his home is burnt. For Assad supporters the spot in the brain where empathy lives has been voided.

I must declare several interests here. I know Dr Sami Khiyami, the Syrian ambassador in London, a highly educated, urbane and amiable man. He held a book-reading for me at the embassy; several of his likeable mates became my mates. Eighteen months ago, the embassy press office organised an enticing visit for me to go and see the country and possibly even interview the First Lady. Imagine that! I wonder which shoes she would have worn, now that we know, through her emails, that she just adores Louboutin. Brought up round the corner from where I live, the lady has been just the most perfect hybrid between East and West.

The meeting never happened because conscience intervened. I knew Syrian prisons were busy torture chambers, where the West allegedly sent their troublesome Muslims. I didn't want to be used for propaganda so I made my excuses. Some Syrians I know are complicit in the regime's brutality. Again, they are not evil, but their collusion is nothing short of evil. That old question, how do decent people lose sight of morality?

Two Syrian London-based doctors, speaking on television, came out with the same guff about plotting Western powers, the great Assad family, the wonderful free health and education system... Why are they hanging around here, then? Sir Andrew Green, who runs MigrationWatch, a resolutely anti-immigration think-tank, is the co-chair of the British Syrian Society. Some migrants are obviously more fragrant than others. Members include relatives of the Assads, immaculately spoken and dressed and, mostly, in psychological denial. Perhaps they party to avoid reality. I told one denier that Syrian drivers carrying first-aid kits were being beaten and imprisoned. Her reply: "Why you worry too much about such little things? We émigrés, we keep quiet and live. Assad will win, it will be OK."

Syrian migrants are under pressure on all sides. An Amnesty report reveals intimidation of protesters by the London embassy and "punishment" meted out to families back home. Some of the Syrians I most admire still risk everything for freedom and democracy. Yet their own side remains suspicious. Walid al-Bunni, a key figure in the Syrian National Council, a doctor who was incarcerated by the regime, said that people in the street don't want "someone who is living in Europe and doesn't know what they are suffering".

On Saturday in London there were two demonstrations to mark the anniversary of the beginning of the unrest. They faced each other, argued noisily, waved their separate flags. Families are divided and some were there on both sides. Something else was visible, just as tragic. Everyone was as distanced from their troubled land as the haranguing man in the mosque. That is the recurring tragedy of exile. You can watch, send cash, but whatever happens you are forever the outsider, the one who wasn't there.

y.alibhai-brown@independent.co.uk