When should terror force a city to shut down?

Updated 8:23 AM EST, Mon November 23, 2015

Story highlights

Juliette Kayyem: Cities are particularly vulnerable to terror and officials face tough choices about when -- and how -- to lock down

Paris, Brussels and Boston have had to confront the choices

Editor’s Note: Juliette Kayyem, a CNN national security analyst, is a professor at Harvard’s Kennedy School of Government, a former assistant secretary in the U.S. Department of Homeland Security and founder of Kayyem Solutions, a security consulting firm. She also is the host of the “Security Mom” podcast. The opinions expressed in this commentary are hers.

(CNN) —  

The attacks in Paris were purposefully targeted to impact a city where people go to eat, drink, watch sports and listen to music. These were no military targets, embassies, mass transit systems, hotels holding foreign officials or government buildings.

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.

Soldiers stand guard in front of the Brussels Central Train Station on Sunday as the Belgian capital remained on the highest security alert level over fears of a Paris-style attack.
PHOTO: EMMANUEL DUNAND/AFP/Getty Images
Soldiers stand guard in front of the Brussels Central Train Station on Sunday as the Belgian capital remained on the highest security alert level over fears of a Paris-style attack.

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?

00:59 - Source: CNN
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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.