"Weaponisation" is the latest threat to the security and prosperity of cities all over the world, says urban expert and leading sociologist Prof Saskia Sassen, a professor at Columbia University in New York, who sits on Columbia's Committee for Global Thought.
A petite and intense woman in her late 50s, she was born in the Netherlands and has lived in South and North America.
Her eyes and brain are focused very much on the future. She is not pessimistic, but certain trends worry her. At the Madrid conference, she warned of knives and guns being adopted on both sides of the law and order divide. "In London, there are moves to give all policemen real guns," she says, with concern. "They have to deal with young violent people, especially in gangs. Gangs used to be just a way of flexing your muscles and making groups cohere. Ironically, it would sometimes make you a better citizen."
But today's gangs are growing more seriously evil and anti-social. "Now it becomes warfare." The problem is worst in certain US and Latin American cities, but London is making an unwelcome run for the title of worst western weaponised city.
Dublin, which Prof Sassen has visited a number of times, is still in the little league, but, as the continual tide of shootings and stabbings demonstrates, we will catch up with this global trend as will others unless something halts the flow."Cities are at war. It is obvious when you look at somewhere like Baghdad, and you had a similar thing in Ireland with Belfast. There is an insurgency that the military cannot defeat, and ordinary people are caught up in it too."
Urban authorities have lost the capacity to transform conflict into another force, she fears. "Cities in history have managed conflict and difference through a complex sort of chaos theory, a fuzzy logic that goes beyond leadership."
A less dramatic, but nonetheless risky, development is the trend to privatise city services. Such policies are "chipping away at public infrastructure". When matters such as transport and health are removed from local government and dealt out to private concerns, the universal obligation of the state provider disappears, Prof Sassen says. She gives an example: "Jaffa, the Israeli city, was very much under threat in the Lebanon war of two years ago. Rockets were falling. The private companies which ran essential services started to pull out. They said it was too dangerous, and they were gone."
And as for the role of immigration, and the future of the inescapable city as backdrop for human existence? "Immigration is a source of conflict, but this can be used to create civic pride and feeling. We are mixed and have been mixed for centuries. Migrants are often open and willing . . . that is why they left their original places. They will adjust.
"Key to this is family, and I think this is the next big challenge for us all, to make sure that cities are familised, and not just habitats for one-bedroom apartments and single people."
Prof Saskia Sassen's most recent book is Territory, Authority, Rights: From Medieval to Global Assemblages (Princeton University Press, 2006)