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