The Christian communities of Syria and Iraq are in the middle of a "cataclysmic crisis", a report warns today. Their very existence is in peril as the world stands witness to one of the greatest threats to the Christian Church in the Middle East since its birth over 2,000 years ago. Christians are facing targeted persecution and leaving Syria and Iraq at an increasing rate, the report says. If this rate of emigration continues, within a few years the Christian communities in these countries will be utterly devastated. It is both unthinkable and unacceptable for a fellow human being, particularly a fellow-Christian, to walk by on the other side, says the charity Open Doors in its report, Hope For The Middle East: The impact and significance of the Christian presence in Syria and Iraq -- past, present and future. The report, written by Open Doors working with Middle East Concern and the University of East London, warns that war in Syria and Iraq has "unleashed a tidal wave of violent persecution". This has targeted the highly vulnerable Christian population and has dramatically accelerated the flight of Christians from Iraq and Syria. Before 2011, Syrian Christians numbered about eight per cent of the population of 22 million. Today about half are believed to have left the country. Before 2003, there were around 1.5 million Christians in Iraq -- less than five per cent of the population. Today, estimates hover between 200,000 and 250,000. As many as eight in 10 Christians are now thought to have left, many with no hope or expectation of return. Many are classed as internally displaced and have sought refuge in other parts of Iraq or Syria. Other have fled to countries such as Jordan, Lebanon, Turkey and beyond, their homes, properties and businesses confiscated or destroyed. Despite the crisis the Christians are facing, Christian Today reported last week that just 51 Christians from Syria have relocated to the UK under the Government's vulnerable persons resettlement scheme. However, Christians make up a disproportionate number of Iraqi refugees. There were more than a quarter of a million registered Iraqi refugees in Syria during 2004-2010. Of these, 44 per cent were Christian. Many of those who do remain want to play their part in rebuilding their shattered societies, the report says. The report says that Middle Eastern Christians are suffering disproportionately and are targeted because they are Christians. Their sufferings include being taken hostage, church leaders assassinated, Christian homes, businesses and churches commandeered or destroyed, women and girls raped and forced into sexual slavery, those living in ISIS territory forced to pay the Jizya tax to survive, and mass forced displacement. Some political bodies have already described this as genocide. "Clearly, Christians are not the only victims. But a previous report from Open Doors demonstrated that Christians were being specifically targeted and were especially vulnerable to persecution," says Open Doors. It is also clear that Islamic State is not the only source of persecution and violence directed towards Christians. Christians face increased harassment and violence from government forces and a range of Islamist groups. Open Doors is calling for current and future legal frameworks in Syria and Iraq to promote and protect the equal rights of all their citizens, for the improvement of living conditions for all citizens and for religious leaders and faith-based organisations to be equipped to play a constructive and central role in rebuilding in Syria and Iraq.