In Damascus there are small but menacing signs of abnormality. Soldiers prevent all but military and security personnel entering certain streets. Heavy goods vehicles are being stopped on the outskirts of the capital because of fear of suicide bombs.

The massacre of the children of Houla and their parents has deepened the sense of crisis here, though many Syrians are becoming inured to violence. Unlike the rest of the world, which focuses on Syria only intermittently when there is some particularly gruesome outrage, people here may be losing their sense of shock after seeing 13,000 die in the last 15 months, according to the latest estimates.

But the most frightening indication that something is wrong is the emptiness, the absence of people and vehicles in previously crowded streets. Many stay at home fixated by a crisis they largely see unfolding on television and online. In the hotel where I am staying in Damascus, I am the only guest.

The government itself often feels curiously absent, perhaps because its attention is elsewhere. Decision-making in Syria was always slow because so many decisions had to be taken at the top but now it is worse.

"I sense that lower-ranking officials do not want to take decisions themselves because they might be countermanded by harder-line officials above them," said a diplomat. At the same time, massacres like Houla, if carried out by Alawite militia men, suggest a leadership not quite in control of its own forces.

The mood is edgy. One person, in the space of a few minutes, shifted from claiming he had total confidence in the happy future of the Syrian people to expressing grim forbodings about the possibility of civil war.

"Why do you foreigners harp on about differences between our minorities?" an anti-government human rights activist asked me in exasperation yesterday. "The French said we would fight each other when they left Syria, but nothing happened. We Syrians stick together whatever governments say about our divisions."

A quarter of an hour later, the same man, a Christian from the city of Hama in central Syria, not far from where the Houla massacre took place, was gloomily wondering about the prospect of sectarian conflict. He explained that Houla is "on a tongue of land where the people are Sunni, but the villages around it are Alawite and Christian. I know it well because my wife comes from a village near there." He said he was very worried that if it turned out that the Sunni villagers, including 34 children, had been murdered by militia men from neighbouring Alawite villages then "I do not know what will happen".

Damascus is deeply affected by the crisis, though this is not always visible. The banks have been cut off from the rest of the world. "All the banks in Lebanon are terrified of doing business with Syria," said one wealthy businesswoman. "My bank manager in Beirut did not want to take a deposit I made even though the cheque was drawn on a British bank." Many in Damascus know first-hand about the physical destruction wrought by the fighting in the centre of the country. There are some 400,000 Syrians displaced by the turmoil, mostly from Homs, who have taken refuge in the capital. Often they move into apartments previously occupied by Iraqi refugees who have returned home, some claiming that for them, Baghdad is now safer than Damascus.