At the moment, the trade has shifted to refugees. This is a labor-intensive operation, and so the syndicates have been furiously recruiting. Europol, the law enforcement body based in The Hague that facilitates cooperation among Europe’s police forces, has registered an astonishing 29,000 individuals in this year alone whom it suspects of involvement in people smuggling inside Europe. There are many more thousands based in Syria itself, Lebanon and across North Africa.

In the past 15 years, Balkan governments have expended huge efforts to reduce the levels of crime and corruption.

Much of this good work now threatens to be undone as the syndicates exploit the chaos on Europe’s periphery to refill their coffers, expand their recruitment and further exert their corrupting influence on governments. In times of instability, criminal structures grow deep roots quickly, which are very tough to remove, especially in struggling economies.

Organized criminal syndicates have changed rapidly since the fall of Communism. They were among the first institutions to exploit globalization to the full. With the expansion of new markets around the world and the emergence of a vast lawless zone for the best part of a decade from Yugoslavia in the west to Russia’s border with China in the east, the 1990s saw a remarkable upturn in the provision of illicit goods and services around the world.

Rob Wainwright, the director of Europol, told me that this has affected “a move away from the traditional family structures of organized crime towards one that is much more multinational.” Add to this the exceptional value of mobile technology and social media networks to criminals, and this renders policing the refugees all but impossible.

This refugee crisis will not go away until a solution to the war in Syria is found, and there is no prospect of that in the near future. So it is imperative in the short term that barriers are brought down. In the last week, borders have been closed, walls built and armed forces deployed. In response, the smuggling groups in the Balkans are simply raising their prices to guide people across the ever more treacherous borders. Meanwhile, the humanitarian situation for all those refugees, whether in Macedonia, Serbia, Croatia or Hungary, reaches crisis levels.

The European Union must agree on and implement a policy for taking refugees across its member states as soon as possible. There are 500 million people in the European Union, and it is perfectly capable of absorbing a further two million, especially since the aging population is already placing immense strains on the Continent’s long-term economic prospects. Many of the refugees from Syria are highly educated and a significant potential asset to the union. Allowing them to stagnate in makeshift camps where despair and criminality are spreading will benefit nobody in the host countries except for those running the underground economy on which the refugees increasingly depend.

The Balkans have come a long way since the wars of the 1990s, but there are still major unresolved political and economic challenges, especially in Bosnia, Kosovo, Serbia, Albania and Macedonia. The longer Europe dithers over its refugee policy, the greater the strain on these countries, not the least being the growing influence of corrupt and criminal structures.