A Useful Reminder

Many people would have you believe that the U.S. has overreacted to the threat of terrorism, and to potential threats such as a nuclear Iran. Unfortunately the U.S. has to take into account worst-case scenarios. Short of a mass infection by a weaponized virus, nuclear terrorism is probably the worst-case scenario. Iran with nuclear weapons is not a great threat to the U.S. directly, because an Iranian attack would bring annihilation in return. But an Iranian bomb in the hands of terrorists is another matter. 

A nuclear bomb detonates in a U.S. city and a terrorist group claims responsibility. Nuclear forensics identifies the bomb as having a 60% chance of being Iranian in origin. Iran denies all responsibility. What do we do? And what exactly would happen if a nuclear weapon went off in a large American city? It's useful to consider the stakes when thinking about such issues. The following article from atomicarchive.com details the effect of a 150 kiloton device exploding in Manhattan. Read the whole article, but here's a chart summarizing the effects:

Distance from 
ground zero (mi.) Population     Fatalities      Injuries       
0 - 0.4                   75,000            75,000         0                   
0.4 - 1.0                400,000         300,000     100,000       
1.0 - 1.5                 500,000         220,000     220,000      
1.5 - 2.5                 1,500,000      235,000     525,000      
2.5 - 4.0                500,000 0      0                    30,000 
Totals                    2,975,000       830,000     875,000     

A 150kt bomb is a significant weapon, but even a much smaller one would be devastating.

A relatively small bomb, say 15-kilotons, detonated in Manhattan could immediately kill upwards of 100,000 inhabitants, followed by a comparable number of deaths in the lingering aftermath.

I would prefer that we did everything reasonably possible to minimize the chances of such an occurrence.