Terrorist networks, especially those associated with Islamic extremism, have targeted Western cities and because of that, cities hold the key to both understanding - and defeating - these terrorists. Like the soldiers in the ancient Trojan Horse, terrorists have infiltrated the cities of their enemy and brought their battle to the streets, gathering places, and centers of power here, and no amount of bombing their cities will defeat them. While that might please those seeking revenge for their terrorist acts, it wages war in the wrong way, brings the fight to the wrong place, and only reinforces their cause and strengthens their networks. Instead, we need our own Trojan horse, deployed in their midst, in our cities.
To do so, we can learn a lot from traditional Islamic cities. As scholars like Besim Hakim and Abd-Al Salam Ibrahim have shown, such cities reflected the Islamic idea of "unity in multiplicity and harmonious wholeness of opposites," as Ibrahim writes. The cities had central mosques, surrounded by markets, administrative buildings, and residential quarters, which had narrow pedestrian-oriented streets that facilitated a strong sense of community, with uniformly unassuming houses whose elaborate interiors captured the sense of external propriety and internal variety that characterizes Islam's harmony of opposites. The "Westernization" of many Arab cities has eroded that urban pattern. More importantly, though, that pattern shows how Western cities - with their anonymous apartment complexes full of strangers, their public spaces dominated by commerce and individual expression, and the marginal role of religious buildings and other sacred spaces - may feel alienating at least to some Muslims.
That difference in form of cities helps explain where and how terrorists have attacked cities in the West. They have not only struck symbols of American power, like the World Trade Center towers in New York, but also displays of personal expression in public places, like the attack on a Parisian sidewalk café. They clearly see the enemy as not just Western commercial and military power, but also the Western city itself and the ways in which people behave in them. And terrorists have also used the city against us. The openness, accessibility, and anonymity of Western cities have enabled them to live among us and to fight us like the Greeks did at Troy, on our turf and, so to speak, within our walls.
How do we defend ourselves against such tactics? As I have written previously, we can defend ourselves, in part, by adopting the same mindset that they use to attack us, looking for vulnerabilities we haven't thought of, like the intentional flying of planes into skyscrapers, and adopting the tactics of home-grown criminals and terrorists, such as drive-by shootings or random mass murder in enclosed spaces. Islamic extremists simply take advantage of what is right in front of us and they use it against us, imagining the unimaginable as a strategic advantage. To defend ourselves, we need to imagine it before they do, combining things not thought of as related, like planes and skyscrapers, and learning from our own criminals about our vulnerability, so that we can anticipate the terrorists and get to a target before they do.
That may seem like an overwhelming task, given the range of targets that exist in open societies such as ours. But understanding traditional Islamic cities can help us predict where terrorists might next attack. Early on, they focused on iconic symbols like the Pentagon and unguarded infrastructure like the airline system, but as we have hardened those places, terrorists now strike building types, like music halls and Western-style hotels, that did not exist in the traditional Islamic city and that run counter to traditional values they hold about propriety in public spaces and the home as the place of hospitality. Wherever the Western city most conflicts with the traditional Islamic one: there lie the most likely targets for terrorist activity in the future and where we should concentrate our defensive efforts.
But we also need an offense against terrorist networks and here, too, the traditional Islamic city offers some clues. The dense and seemingly impenetrable networks of streets and passages in the residential quarters of such cities depended upon close relationships among people, with many of these sectors named after the clans that originally inhabited them. The terrorist cells of Islamic extremists seem to have some of the same characteristics: complex networks of connections among trusted compatriots, which make them hard to penetrate and almost impossible to defeat in conventional ways. Research has demonstrated how to use game theory to identify the key members of terrorist networks, but this work also shows how taking out central players may have little effect on the network itself; new links form among the remaining people, new members join the network and make new connections, and others become more central, replacing those lost. Like an evolving residential quarter in an Islamic city, people come and go, but the neighborhood remains.
This suggests that the defeat of terrorist networks may come, not just from the elimination of key members, but also from the disruption of the networks themselves. Such networks depend upon bonds of trust and dependable communication. Once trust and the reliability of communication breaks down, the whole ceases to function well, as happened when traditional Islamic cities became more Westernized and relationships among people in residential quarters changed. That may happen naturally as extremist groups recruit from the West, although accelerating the process by infiltrating the networks and rendering them dysfunctional seems prudent. And for the recruits for such counter-terrorism, we might look no further than the very people uprooted by Islamic extremists, now moving across Europe. The terrorists' weaknesses, as they have shown us, become our strengths; their outcasts, our allies.
Thomas Fisher is the Director of the Metropolitan Design Center at the University of Minnesota.