Spark wrote:
As for dirty bombs themselves: as actual weapons doing physical damage, they're not much better than ordinary bombs. The radioactive fallout will only be dangerous to a very localized area and will be very unlikely to hurt a lot of people.
Psychologically, though...
Actually, a shipping container of radioactive material entering NYC would shorten the lifespans of hundreds of thousands of people.
As I said before, I was given a lecture on maritime security. The worst case scenario that the US Coast Guard came up with after 9/11 was a large amount of radioactive material being smuggled into a large port (such as NYC's) and being allowed to sit there. No explosion involved. Estimates put the fastest possible reaction at over six hours due to the time it would take for somebody in a hospital to diagnose radiation sickness and then to track the exposure back to the source. Hitting a port like Hong Kong, New York, Rotterdam or Shanghai would do major damage in terms of human lives.
That's why international maritime shipping security codes and many national laws (including Australia's) were changed to tighten the virtually non-existent security measures being taken. Now it's exceedingly difficult to pull of something like that.