As populations shift they can bring benefits to their hosts or put more pressure on these communities

The Earth’s population is rising dramatically. By the year 2030 more than 9bn people will inhabit the planet. As the population grows and resources are put under more stress there is pressure for people to move away from their place of birth, usually in pursuit of economic opportunities or personal profit. As populations shift they can bring benefits to their hosts or put yet more pressure on the communities to which they move.

Migration is one of the defining element of globalisation. Combined together jet travel and the internet have shrunk the earth. Modern advances like these enable distinct groups of people to disperse from their traditional homelands while at the same time retaining a distinct sense of common identity. These diasporas maintain a link with their homeland and each other through the internet and cheap air travel, explains Rear Admiral Chris Parry, formerly a Royal Navy strategist. “But the problem with diasporas is they transmit both risks and opportunities.”

While the free movement of people has benefited mankind enormously, both in terms of economic liberalism and multiculturalism, it also has the potential to spread risk. Witness the rapid reach of pandemics like SARS, avian and swine flu. Diasporas can take even more threatening manifestations, such as ideological or religious extremism. A small minority of disengaged young Muslim men living in Britain feel sufficiently aggrieved to turn to terrorism. The would-be terrorists feel more connected to the dangerous world of religious extremism via cyberspace than to the British communities in which they have lived most of their lives. These dangers and others have forced governments to impose restrictions on international travel and erect walls, literally in the case of the US barricading its border with Mexico.

The graphics below show two classic diasporas. The Lebanese diaspora maps the geography of its trading settlements over the past century, while the current distribution of Greeks comprises a mixture of early colonies, trading settlements in Africa and labour migration to North America. Another classic diaspora is that of the Chinese. As a result of the decline of the Chinese empire in the 19th Century and its turn to Communism in the 20th many Chinese citizens left the country, which inadvertently helped China establish a huge global presence. More recently China’s one child only policy has led to a massive demographic imbalance.

Parry, who used to head a Ministry of Defence unit tasked with identifying future threats to Britain's security, says: “The huge demographic imbalance in China means that in ten years they could end up with 22m ‘spare’ 18-25 year olds.” Pushed out into the diaspora these highly educated stateless young Chinese men could pose a risk to Western countries, warns Parry. Macho youth combined with low economic prospects can cause problems, he says, sometimes typified by organised criminal activity.

The fact that there is very little pressure on diasporas to integrate into their host countries does not help. In most cases they maintain stronger contact with their home countries. Multiculturalism, where immigrants are encouraged to retain the culture of their country of origin, is pursued in Canada, Australia, the Netherlands and the UK. But it has been called into question recently after events like the London transport bombings in July 2005 and the murder of radical right wing politician Pim Fortuyn in Holland in 2002. Both crimes were committed by angry individuals from an ethnic minority. The US experience of homegrown terrorism is different to that of the UK, where it is more common. This is sometimes attributed to the US model of encouraging immigrants to assimilate with the dominant culture. Although this argument has also been called into question recently as the US has itself suffered from homegrown plotters.

Despite these risks mass migration can bring many benefits. The UK construction and service sectors have benefitted for a number of years from a deep pool of highly skilled and hard working Poles. The Polish diaspora is one of the UK’s biggest. As well as providing the host country with a talented workforce this migration has helped spread economic rewards.

Some developing countries have become dependent on their diaspora for much needed income. Remittances by expatriate workers back to their home countries topped $316bn in 2009, a five fold increase over 1990 inflows. These capital inflows constitute a vital chunk of GDP in some countries (40% in the Democratic Republic of the Congo and over 20% in Lebanon and Moldova).

Provided they are allowed and encouraged to integrate diasporas can bring many benefits to their host country. Young technical wizards from China, for example, could provide a major boon for the high-tech industry in the UK or another major European market. Most countries recognise this and seek to increase the number of skilled migrants to fill specific job requirements, particularly in the fields of health and information technology. And skilled migrants tend to be looked upon more favourably by the citizens of receiving countries. Some countries, like the Philippines specifically train nurses for the global market. Globally the skilled, however, make up a minority of all migrants, but the figures are increasing.

There may be little that risk managers can do other than be aware of these trends. The reality is that networks of people exist across the world exploiting opportunity and creating risk depending on their own motivations.