Instead, restaurants, a sporting arena and a concert hall were chosen because they represent the very benefits of urban life and the vulnerabilities of a crowded space. The Paris tragedy is of such consequence because it was an attack focused on the young, the social, the future: the very heart of every city.
If this is the wave of the future, then every city is inherently vulnerable. What makes them vital -- their very openness -- also puts residents at risk. For public safety officials, what to do about threats in a city is a constant balance between the risk and the reward. And it is in this context that the decision for an indeterminate lockdown must be considered.
This weekend in Belgium, in response to specific and presumably credible intelligence in the hunt for the Paris terrorists, Brussels went into lockdown. The decision has now been made by the Prime Minister to extend the lockdown through Monday, a work and school day, at the very least. The economic and psychological impact are immeasurable.
Belgium is in the midst of a counterterrorism mission, and we must rely on its good-faith efforts to protect the population and thwart the next attack. But Belgian leaders' decisions expose a major challenge in security efforts and one that needs to be prioritized for a future when most cities are likely to have to respond to threats of terror: How do you close down an entire city?
Given mobility of people and mass transit systems, cities can find it impossible to try to limit the impact -- or what we in disaster management call the cascading consequences -- of a shutdown.
Mass transit systems are a perfect example.
During the Boston Marathon bombings and the subsequent chase of the Tsarnaev brothers, city and state public safety officials believed it was important to shut down areas of Boston as they pursued Dzhokhar Tsarnaev. What they found, however, was that the system of mass transit was so intertwined -- buses leading to trains, and vice versa -- that to close down a single part of it was impossible. It was all or nothing. And they chose all, closing Boston and surrounding suburbs for a day.
This will be true for most cities.
Therefore, emergency response planners should begin to make plans for the potential of closures that are the least disruptive. Most training around city closures, especially in the context of snow storms or hurricanes, assumes that systems are either running or not. It may be in the context of the threat environment that leaders -- not just public safety leaders, but those in transit and design -- need to develop more limited responses.
But, assuming that isn't possible, the next step must be to ensure that criteria are well established for when a lockdown occurs and as importantly, when it will be lifted.
It cannot simply be that a terrorist has gone missing; that would mean every major city would be in constant shutdown. Such criteria could include the specificity and veracity of the intelligence and the likelihood that the attack would be thwarted by a shutdown.
Cities and nations must have very clear criteria for when and how they will reopen. In Boston during the marathon bombing in 2013, the governor reopened the city before Dzhokhar Tsarnaev was captured. The city struggled to explain how it could convince people that things were safe while there was a terrorist still on the loose.
As it turned out, it was because the lockdown was lifted that a suburban resident saw traces of blood and alerted the police to where Dzhokhar was hiding, suggesting that the "crowds" can often be used to help in counterterrorism efforts.
I don't know, in the absence of a major arrest, how Brussels moves forward after Monday. The country is rightfully on edge, made more so by being told to stay put. The economic impact of a lost business day alone will be felt throughout the country and much of the EU.
The psychological impacts only aid the sense that that terrorists have changed how we live. Thus, shutting down a city is a tactic that should only be used in the rarest of circumstances, based on criteria that are known to the public and that are understood by those who implement them.
From public accounts, Belgium chose to close the city because of an imminent threat and the hunt for the terrorist, Salah Abdeslam, responsible for the French bombings.
Only they can make that judgment call, and there is no "right" answer about what they should have done. But, at some stage soon, there has to be a return to normal, and to do so, leaders need to publicly set the stage for how the city's engines of activity will start churning again, especially if the elusive Abdeslam is not found.