In his third book, David Kilcullen takes us out of the mountains: away from the remote, rural guerrilla warfare of Afghanistan, and into the marginalised slums and complex security threats of the world’s coastal cities, where almost 75 per cent of us will be living by mid-century. Scrutinising major environmental trends - population growth, coastal urbanisation - and increasing digital connectivity he projects a future of feral cities, urban systems under stress, and increasing overlaps between crime and war, internal and external threats, and the real and virtual worlds. Informed by Kilcullen’s own fieldwork in the Caribbean, Somalia, the Middle East and Afghanistan, and that of his field research teams in cities in Central America and Africa, Out of the Mountains presents detailed, on-the-ground accounts of the new faces of modern conflict - - from the 2008 Mumbai terrorist attacks, to transnational drug networks, local street gangs, and the uprisings of the Arab Spring.