Terror response math

Suspect bomber Dzhokhar A. Tsarnaev has been captured after a historic manhunt in the Boston metro area.  Part of what was historic about it was the response of law enforcement officials and politicians to the situation in which they closed significant parts of the city.  Numerous educational institutions were closed.  Trains and buses were closed.  Residents were told to lock themselves in their houses and not go out.  In listening to the radio at one point a room full of experienced new correspondence were asked if they had ever experienced this type of response anywhere in the world and they all claimed it was novel.

Boston in lock down

Boston in lock down

So i am legitimately torn here.  i dont want terrorists to succeed.  This is a very dirty game, the use of violence on non-combatants to advance your political goals.  So perhaps this extraordinary response of locking down hundreds of thousands of people will be sufficiently discouraging that some other terrorists will not strike, knowing that their chances of disappearing into a crowd (for example) are greatly diminished because extraordinary tactics are likely to be used to catch them including closing entire cities.  Were this to have a chilling effect on terrorist attacks this might well be a good thing.

But i remember a calculation which was done by Car and Driver magazine after speed limits were dropped from 70 mph to 55 mph in response to the Arab Oil Embargo in 1973.  Besides saving gas, one of the things proponents of dropping the speed limit pointed to was the dramatically reduced number of auto fatalities the reduced speed limit ushered in.  Car and Driver then pointed out that for every life saved there were an additional 102 person years spent driving, because it took longer to get many places.  So we did save a life and we spent a life an a half in the car driving to save it.

Wikipedia lists 26 terrorist acts in the US since the year 2000.  That is 2 attacks per year.  Let’s do some impossible math for a few moments.  Let’s say that this extraordinary response to the Boston Marathon bombings discourages half the attacks on the US, so this rate drops to 1 per year.  Let’s say that 1/4 of the lives of the approximately 1 million people locked down for 11 hours was “lost”.  [The locked down region included the cities of Watertown, Newton, Waltham, Belmont, Cambridge, Arlington and the Allston-Brighton neighborhoods of Boston.] That works out to something over 300 person years lost to stop an attack a year.  Perhaps this is cheap.

They are all in search of a single man

They are all in search of a single man

What i fear is that state saying “we now have this new power to shut off infrastructure (transit, schools, health services) when ever we feel like the threat is great enough.”  Who makes sure this power is not used inappropriately?