In a square in Nazareth, right below the Basilica of the Annunciation, a Koranic verse warns that "whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers". Yet it is the spectre of losing in the here-and-now that most haunts the dwindling number of adherents to Christianity in the land of its birthplace. In the hometown of Jesus, where it all began two millennia ago, Christians feel under siege. This fear is not limited to Nazareth or the Holy Land. Across the Arab world, Christians ask whether they are an endangered species: threatened by Islamist radicals; forced by limited opportunities at home to seek new lives abroad; accused of complicity in the schemes of foreign predators; and now menaced by the wave of revolution ripping through the region -- which some fear could uncover the submerged hard-wiring of sectarianism. Two massacres, at the church of Our Lady of Salvation in Baghdad last October and at a Coptic church in Alexandria on New Year's day, have reinforced this sense of a modern persecution aimed at emptying Arab lands of Christians, who number perhaps 15m among 300m Muslims. "We are in a new era of persecution of Christians," says Rifa't Bader, a Jordanian Catholic priest whose congregation is now mainly made up of refugees from jihadist savagery in Iraq. "We are victims of things we are not responsible for, whether the Israeli occupation [of Palestinian land] or American policy in the Middle East, especially [the occupation of] Iraq". Iraq is a case apart. Following the Anglo-American invasion of 2003, indigenous Assyrian Christians, mostly Chaldean, have endured a backlash that has reduced their numbers from close to 1m to about 400,000. One refugee in Amman, a 66-year-old chemistry professor who gives his name as Abu Sinan, says: "In my country, 1,400 years of co-existence and common endeavour with Muslims disintegrated in just five years." To Arab Christians around the region, this was a tragedy foretold. Riah Abu el-Assal, a Palestinian and former Anglican bishop of Jerusalem, says one month before the invasion he personally warned Tony Blair, British prime minister of the time, that "you will be responsible for emptying Iraq, the homeland of Abraham, of Christians". After almost 2,000 years, Iraqi Christians now openly contemplate extinction. Some of their prelates even counsel flight. Maher, 24, used to guard churches from attack in his formerly mixed Baghdad neighbourhood of al-Jadriya, where he says only five Christian families remain. He is now waiting in Amman to join the survivors from his family in the US. "Eventually my choice became simple: whether or not to stay alive," he says. But if Iraqi Christians scent apocalypse, their Arab co-religionists elsewhere have started to feel vulnerable in the lands of their forefathers -- even if some are exhilarated by the current chain of uprisings bringing a fresh vision of freedom and democracy. In Egypt, the resolutely anti-sectarian Tahrir Square revolution was followed by riots between Copts (reckoned to amount to about 10 per cent of Egyptians) and Muslims, raising suspicions that elements from the deposed regime of Hosni Mubarak were trying to widen a cleft between the two communities. In Jordan, the Christian minority has prospered under the protective wing of the Hashemite monarchy, owning or running about one-third of the economy although they form less than 3 per cent of the population. Gathering resentment against corruption and economic hardship could threaten its position, as well as that of King Abdullah. In Syria, where Christians make up some 10 per cent of the population, they are closely aligned with the regime of Bashar al-Assad -- essentially rule by the Alawite minority exercised from behind the facade of the Ba'ath party. "Their fear is that if the regime falls to the Sunni majority, they will be put up against the same wall as the Alawites," says one close observer of Syria in Beirut. The Assad regime has enforced religious tolerance. Syrians, having seen sectarian demons uncaged in Iraq and before that Lebanon, worry about a new Balkans-in-the-sands now the regime faces unprecedented dissent. Raymond Moussalli, a Syrian and Chaldean priest in Amman, whispering through a sung mass in Aramaic -- the language of Christ still spoken by a few Syrians -- says: "If sectarianism enters into the Syrian equation the whole region will explode, especially Jordan and Lebanon." The Christians who previously ruled Lebanon, pre-eminently through the Maronite sect, emerged defeated from the 1975-90 civil war and are now divided between factions allied with the Shia Muslims, led by Hizbollah, and the remnants of the old Phalange party, who have cast their lot with the Sunni. War and emigration have reduced their numbers to about one-third of the population. Yet Lebanese of all sects often manage to do well abroad, especially in finance and service industries, while keeping ties to home. For many Arabs, moreover, able Christians offer a culturally comforting window on the world, says Kamal Salibi, a Lebanese historian. "The Gulf is a Levantine colony. The Levantines do not exercise political power but they take away a good chunk of the money. They are preferred to everyone else," he adds. "The Saudis in particular prefer the company of Lebanese and, not only that, of Christian Lebanese." In Israel and the occupied Palestinian territories the pressure to emigrate is intense, if equal for Muslims and Christians. But Christians, often because they have better education as a passport, are more likely to leave. This phenomenon dates from Ottoman times. Yet when Israel seized Arab east Jerusalem in the 1967 Arab-Israeli war, there were 28,000 Christian Palestinians. Now there are about 5,000, their numbers still shrinking. Bishop Abu el-Assal points to the Latin Quarter of Nazareth, traditional stronghold of the Roman Catholic, Greek Catholic and Maronite churches. "I doubt whether it's 5 per cent Christian now," he says. His Anglican bishopric was established by the King of Prussia in 1841. Long before that, however, Christians were in the vanguard of Arab endeavour. Chafing under the Byzantine yoke, they aided the Caliph Omar's conquest of Jerusalem in 638 and Saladin's recapture of the holy city from the crusaders in 1187. Raouf Abu Jaber, an Oxford-educated historian who heads the Greek Orthodox council for Jordan and Palestine, says: "I remind Muslims they would not have been able to take over these lands were it not for the support of the indigenous Christian people, who were Arabs." Christians -- as well as Jews -- helped the rise of Islamic civilisation by plugging it into the Hellenist legacy. In its decline, they were custodians of this heritage and of the Arabic language. It was Christians who disproportionately drove the "Arab awakening" of the 19th and 20th centuries, not just through a new Arabist politics but in education, publishing, medicine and science. Open to the world and set against the Turkic-centred late Ottomans, Christian Arabism had a sound logic. "Arabism was launched by the Christians, partly as a form of self-defence against the Ottoman Turks," says Fadi Malha, a Maronite lawyer. "It obviously couldn't be Sunni Islam; that was the religion of the empire." Pan-Arab nationalism, however, became the alibi of a network of Sunni strongmen, generally supported by the west. It turned out to be an ideological wild goose chase into an autocratic dead end -- which Christians abetted. "Christians have become too elitist, linked to the status quo and cocooned in their minority status," says Philip Madanat, an evangelical activist in Jordan. "They are not spearheading reform as they used to. They are losing pre-eminence, supporting diversity but clinging on to these regimes, ready to depart if things go awry, whereas their duty is to be protagonists of social change." Prince Hassan bin Talal, brother of the late King Hussein of Jordan and a lifelong advocate of interfaith dialogue, says Christians "have to their credit advanced the separation of religion and state in the interests of Arab nationalism" but that "the Christians of the east have to do a lot more to develop their own storyline". "The threat is not only to Christians but to Islam, to religion as a whole. The only way to stop extremism is to develop moral authority," he argues. In the post-Ottoman era the problem is partly that understanding of state, nation and authority are all mixed up, along with Muslim attachment to the Ummah, the worldwide "nation" of Muslims -- which, for some, gives an Indonesian Muslim precedence over an Arab who is Christian. Could all that now be reshaped, in the crucible of the new Arab awakening? Some Christians think so. Tareq Mitri, a Lebanese cabinet minister formerly at the World Council of Churches, says that the Islamist rise he dates from Iran's 1979 Islamic revolution "partly explains why many Christians support existing regimes" -- especially when Arab rulers blackmail their citizens and the west into belief that the only alternative to their despotism is Islamist theocracy. But "with what is happening in the region, people are seeing the Islamists are not as influential as they seemed to be". Mr Madanat argues that "these young [revolutionaries] are not doing this because they are Christian or Muslim. They want change [and] we need this beacon of light." Yet some of the Maronites, hitherto seen as a barometer of Christian well-being in the region, still manage to convey superiority alongside vulnerability, preferring to live in a tribal past than a plural present. Samir Franjieh, a centre-left intellectual from a leading Maronite clan, sees an opportunity. "If Muslims and Christians take part in a common struggle for the same values, the problem of coexistence is resolved. We have to foment a new nahda [awakening] in this part of the world and the way forward is for Christians to play a proactive rather than defensive role [in] a new Arabism, democratic and plural rather than nationalist." Even Abu Sinan, the Iraqi refugee chemistry professor, is moved to think about more than his own future. "There is more hope after these shebab [youth] revolutions. They have young and open minds, and are creating their own future with their own hands. Our mistake has been to glorify generals rather than scientists." Yet the spectre of an eastern Mediterranean empty of Christians is still haunting for many, not just because it would uproot a 2,000-year-old heritage but because it would burn the bridges between east and west. "The beauty of this land is that it is a mosaic," says Bishop Abu el-Assal in Nazareth. "If the Christians leave, what will be left of that? The Middle East represents the intermingling of civilisation and the three Abrahamic faiths. If that finally goes, this will cease to be Terra Santa; it will be a museum."