Having said that, we must also ask about the causes of the crisis and what can be done to address them. We have to ask too about the role of international agencies in the crisis, as well as that of regional powers.

Although only a minority of those on the move are actually from Syria, it is quite clear that it is the multi-faceted civil war there which has given a fresh impetus to people from different parts of the world moving towards Europe. Before the conflict, there was a commonly understood trade-off in Syria: a degree of religious and personal freedom in exchange for restrictions on political freedom. Many, if not most, Syrians accepted this situation, even if with resignation, as necessary in maintaining peaceful coexistence among the many ethnic and religious groups there. This status quo was fatally disturbed by the Saudi and Qatari backing for those elements of the Muslim Brotherhood and other Sunnis who, under cover of the so-called Arab Spring, wished to exact revenge on the present President Assad and the Ba'ath party for what the elder Assad had done to them in the 1970s and '80s. The West's ill-judged support of its allies, in their support of a Sunni Islamist rebellion against a secular state dominated by the Alawites, completed the ingredients for the powder keg which has exploded with such dire consequences for Syria itself, its neighbours and now Europe.

The resolution of this conflict must be a top priority for Europe's politicians and for the international community. Many within Syria will agree that there can be no return now to the status quo ante. A new settlement is needed that will guarantee the participation of all its diverse communities in the political process. Prior to that, a transitional period will be needed and I am glad that the West is now increasingly prepared, even if under Russian pressure, to allow President Assad and the present regime to remain in power during this period. The West has to learn that, in the Middle East, the choice is not between angels and monsters but between different kinds of monsters. In such a situation, Assad is by no means the worst of them. We must pray and work for such a settlement as it will allow the hundreds of thousands of internally displaced people, as well as the refugees in camps in Turkey, Jordan and Lebanon, to return to their homes.

The bulk of those fleeing Syria are in the vast refugee camps in neighbouring countries. It is only the relatively well-off who can rent homes in the host countries or try to travel further afield. Although the camps are not the worst in the world, life in them can be pretty grim. The British government is right to put the emphasis on improving life in the camps with better shelter, food, medical and educational facilities. It is also possible through the use of micro-enterprise initiatives to provide some gainful occupation to the women and men in the camps. This will ease the pressure to exit from them as soon as possible and in whatever way possible. It is also right to prioritise people for settlement in the UK who are most vulnerable, rather than simply to accept anyone who has the resources and the wits to arrive in Europe and seek asylum.

Those who do arrive in European or in other safe countries should be received humanely and their cases processed speedily. Countries on the migration front line like Greece,Italy and Malta cannot be expected to bear the burden of numbers, and the disruption of civic life which this can cause, on their own. They must be assisted in this way not only by their European neighbours but by the international community. The latter, through the UN High Commissioner for Refugees (UNHCR), needs also to take responsibility for the resettlement of those who are genuinely shown to be refugees. Europe should, of course, play its part but this is a global issue. The United States and Canada, Australia and New Zealand and South America all have a part to play, whether because of previous involvement in the Middle East or because they are now home to communities from the region. What about the Arab League and the Organisation of Islamic Cooperation? Some of the member states of these two organisations have played a significant role in accommodating refugees from Syria, but what about the others? Do the organisations themselves have a plan for refugees? It is sometimes claimed that some of these states have been very generous in sending aid and equipment to the refugee camps. This is, indeed, very welcome but generosity at a distance is not enough. Recognising the refugee issue as a global one will defuse tension within Europe and between Europe and the rest of the world. It will also help to distinguish genuine refugees from those who are merely economic migrants.

Generally speaking, European demographics are in meltdown. In a number of countries the birth rates are such that the population is not being sustained. At the other end of life, there is an increasingly ageing population, which needs care and medical attention. Who is going to pay for this? One solution is to look to immigration as a panacea for Europe's problems. Not only are immigrants highly motivated to work, they will often do work which Europeans find undesirable. Many immigrant communities, moreover, have high birth rates and thus contribute to easing the demographic crisis somewhat. Does this justify Germany's decision to welcome large numbers of those fleeing Syria? It would certainly ease its demographic crisis and provide it with highly motivated workers -- at least for this generation.

The decline in Europe's population has much to do with social factors such as the weakening of the natural family, the changing social and economic roles of women and children being seen now as a burden, limiting people's lifestyles, rather than as a gift to be nurtured and enjoyed which fulfils the lives of parents. If not exactly the "culture of death" which Pope John Paul II warned us about, it certainly hasn't been the "culture of life" which he was concerned to commend. If Europe is to slow, and even to reverse, its demographic decline, however, it will need more than moral exhortation alone. It will need family-friendly and, specifically, children-friendly fiscal policies. Instead of policies driving parents back to work as soon as possible after the birth of their child, a focus on good parenting skills would be of huge benefit to the parents themselves, their children and society at large. It will need a shift in value systems so that bringing up children is seen as valuable in itself and, perhaps, socially more useful than some of the non-jobs we have created for ourselves and to which we are hurried back by a nanny state.

In all of this, immigration has a place but it must be the different countries which should decide what their needs are and how immigration can help them in meeting such needs. The creation of jobs must be carefully balanced so that the existing population is not left out of the market because others are willing to work for less or in sub-optimal conditions or without security of employment. At the same time, Europe has a responsibility for not simply creaming off the best talent from poorer countries and must provide for opportunities across the employment range. It is also not morally acceptable to develop immigration policies which discriminate on the basis of race or wealth.

Given the disturbed world in which we live, whether we like it or not, refugees will keep coming, even if, hopefully, not in the numbers we have seen recently. It is most important, with the help of international and voluntary agencies, to discern those who are neediest and the most at risk. In this, past experience of capture, torture or being attacked must be taken into account, as must belonging to an ethnic or religious group. In the present conflict in the Middle East, it is clear that Christians, Yazidis, Mandaeans and Druze, for example, are at special risk because of their religion and/or their ethnic identity. On the one hand, it is irresponsible to neglect factors which lead to special vulnerability. On the other, these are the very groups most likely to integrate well into European society.

Integration must, indeed, be the watchword. This time around, experiments in multiculturalism must not be repeated. Communities should not be left alone to organise their own communal lives. There must be a sense of belonging to society on every side. New arrivals should not be allowed to be housed in ghettos, schooled in them and provided with services which create and strengthen isolation. There needs to be engagement and exchange from the very beginning. The sharing of a common narrative should be encouraged from primary school onwards, as should a view of common citizenship and the equality of all before the law. Whilst new arrivals should be afforded every assistance in accessing social, medical and educational services, there should be an expectation that, sooner rather than later, the lingua franca will be used in their delivery. In terms of higher education and employment we should plan for mobility between communities rather than isolation within them.

We have witnessed how isolated and segregated communities, and especially the young among them, have been exposed to extremist radicalisation. Religious places of worship, community centres, schools, student societies, prisons and much else besides, have been used to nurture grievances against host societies and to convert the impressionable to radical religious ideologies. In terms of community engagement, funding and worldviews which may lead to subversion and violence, there has to be constant vigilance on the part of communities themselves and also of government.

We can be sure that among those arriving in Europe are radical Islamists who will wish to use this mass movement of people to infiltrate and implant sleeper cells for future terrorism in Europe. Whatever methods are used to distinguish genuine refugees from others, this factor has always to be kept in mind. We are facing not a nationalist ideology or a liberation movement or even a localised religious revival: we are confronted with a globalised religious ideology which has world domination in its sights. The events of the last year or so should sober up those who say, "It'll never come here." It has -- and unless we wake up and address the threat directly, we may find ourselves refugees fleeing its wrath.

We should not harden our hearts and we must show compassion for the needs of refugees, but this should not be confused with or substituted for a proper analysis of the global situation and the need to develop appropriate policies of response to it. This is a time for using both our hearts and our heads, and to give each its due.

The Rt. Rev. Michael Nazir-Ali is the former Bishop of Rochester