British Christian leaders are the latest to urge caution as MPs prepare to vote on military action in Syria.
The Archbishop of Canterbury Justin Welby said the impact on those people not directly involved in the fighting was "beyond description and horrible".
He said: "The things which MPs will have to bear in mind in what is going to be a very, very difficult debate is firstly: are we sure about the facts on the ground?
"Secondly: Is it possible to have a carefully calibrated response including armed force, if you are sure about the facts on the ground, that does not have unforeseeable ramifications across the whole Arab and Muslim world?"
"I have had a lot of conversations with people in the region. I think the overwhelming sense is of a really moving and terrible sense of fear about what might come out of, what might be happening in the next few weeks - not predicated on people doing one thing or people doing another, just a sense that this a terribly, terribly dangerous time," he told the Daily Telegraph.
The hardship experienced by Christians in Syria has prompted many to take a position on the conflict. Syrian Christians, who have for the most part been stalwart supporters of Assad, fear being killed or driven from their homes if jihadist-linked rebels become the dominent force.
Earlier this month, militants were reported to have shot 11 Christians, outside Ein al-Ajouz in central Syria. And in April, two bishops were abducted and an Italian Jesuit priest, Father Paolo Dall’Oglio on a trip to the rebel-held northeastern city of Raqqa.
Archbishop Welby, who visited the region in June, said the situation had deteriorated since his visit.
He said "I think it has got worse since then. I can scarcely remember a time of being in meetings where there was such a sense of apprehension, I mean it was tangible, this sense of 'What will happen? What will be the impact on us?'....the impact on people not directly involved in the fighting is beyond description and horrible".
He added: "I am extremely conscious of my own lack of knowledge having spent a lot of time in the area over the years very much in the reconciliation area, so dealing with the people involved in these things.
"I am deeply, deeply aware of the enormous complexity and inter-linkedness of everything that happens there."
He acknowledged, however, that the Government was better informed than he, making clear that he had no sense that politicians were "slavering" to "unleash the dogs of war".
Bishop Antoine Audo of Aleppo told Vatican Radio that Pope Francis was calling for international pressure and negotiations on Syria, but not military intervention.
“If there were a military intervention, I think this would lead to a world war, there is this risk. ” the bishop said. “What we hope for is an international effort that will help dialogue and not make war”.
Dave Landrum, director of advocacy at the Evangelical Alliance, went further, suggesting that military action would cause far more bloodshed.
"We have got a proxy war that exists right now that's being fought out in that area between Russia and America, between America and Saudi Arabia and Iran, between other countries on the ground, between Islamic extremists and Islamic moderates and an internal Syrian conflict trapped in a war on terror," he told reporters.
"I think to light a match in the middle of all that - which is what an intervention would represent - would be disastrous. I'm not sure what could be achieved.
"I think the only way forward is diplomatic - I don't think there is a military answer to this. I think it may play well in domestic politics but I can't see it achieving much."
Paul Parker, recording clerk for Quakers in Britain, said that they "understand - and share - the wish of the international community to take some form of action to reduce the bloodshed, but we strongly urge those who are tempted to respond militarily to think again."
“Air strikes will kill people just as surely as chemical attacks," he continued. "All weapons must seem equally abhorrent if it is your family that is being killed. Punishment for use of specific kinds of weapon is no justification for further acts of war or for supplying yet more weapons.
“New participants in a war will breed new hatreds. Experience of other conflicts shows that supposedly simple or 'surgical' military interventions usually become messy and hard to end.
“We beg those in power to work with diligence through the United Nations and all diplomatic channels to bring peace nearer. We challenge them to use their resources and imaginations creatively. Please don't fall into the old trap of thinking that taking any action is bound to be better than doing nothing."Suggest a correction